The milling of pristine and brominated P-100 graphite fibers

Techniques were developed for the ball milling of pristine and brominated P-100 graphite fibers. Because of the lubrication properties of graphite, large ball loads (50 percent by volume) were required. Use of 2-propanol as a milling medium enhanced the efficiency of the process. Milled brominated P-100 fibers had resistivities which were indistinguishable from milled pristine P-100 fibers. Apparent loss of bromine from the brominated fibers suggests that bromine would not be the intercalate of choice in applications where milled fibers of this type are required. Other intercalates which do not degas may be more appropriate for a milled fiber application. These same results, however, do provide evidence that bromine molecules leave the fiber surface when removed from overpressure of bromine. While exploring possible solvent media for milling purposes, it was found that brominated fibers are stable in a wide variety of organic solvents

An integrated science unit : ants

This instructional development project integrated language arts and the science areas. A print-rich environment extended content and offered models of language, thus energizing children to become actively involved in the study. Many literature genres and.related expressive activities provided children with many options for learning experiences. The focus for this science unit for grade two was on ants. A print-rich environment was provided along with computer software and access to information on the internet

Bacterial Dehalogenation of Mixtures of 1,2-Dichloroethane, 1,2-Dichloropropane, and 1,1,2-Trichloroethane by Dehalogenimonas

The goal of the research presented here was to assess the ability of two bacterial strains, Dehalogenimonas lykanthroporepellens BL-DC-9T and Dehalogenimonas strain IP3-3, to reductively dehalogenate four contaminant mixtures comprised of combinations of the chlorinated solvents 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA). Both of these bacteria were first isolated from contaminated groundwater at the PetroProcessors of Louisiana, Inc. Superfund site located near Baton Rouge, LA and are of interest because of their novel abilities to transform halogenated alkanes. In previous work (Yan et al., 2009, Bowman et al., 2012), it was demonstrated that both strain IP3-3 and D. lykanthroporepellens BL-DC-9T were able reductively dehalogenate 1,2-dichloroethane, 1,2-dichloropropane, and 1,1,2-trichlorethane when present as individual contaminants. The effects of these compounds as co-contaminant mixtures have not been thoroughly examined until now. Whether transformation of multiple contaminants occurs concurrently (i.e., both compounds transformed simultaneously) or sequentially (i.e., one compound transformed before the other) has important implications when assessing fate and transport of these contaminants in the environment. The experimental protocol involved inoculation of the strains into anaerobic media that had previously been amended with all three possible binary (i.e., two-component) mixtures as well as a three-component mixture. Duplicate batch serum bottles were repeatedly sampled at multiple time steps to assess contaminant transformation over time. Chlorinated solvent depletion and daughter product formation was determined by analyzing both the aqueous and gas headspace concentrations via gas chromatography. Preferential dechlorination of 1,1,2-TCA over both 1,2-DCA and 1,2-DCP was observed for both strains. In the combination of 1,2-DCP and 1,1,2-TCA, 1,2-DCP was not converted to propene until the 1,1,2-TCA aqueous concentration was relatively low (i.e., in the tenths of a mM range). Similarly, when 1,2-DCA and 1,1,2-TCA were present as co-contaminants, 1,2-DCA was not converted to ethene until the aqueous 1,1,2-TCA concentration were lower (i.e., \u3c0.1 mM). When the strains were exposed to a combination of 1,2-DCA and 1,2-DCP, both compounds were utilized concurrently over a comparably large range

Changes in Pharyngeal Airway Dimensions Due to MARA Treatment in Class II Malocclusions

Orthodontic treatment effects on the pharyngeal airway have recently become a hot topic in the field of orthodontics. Current literature has shown facial skeletal morphology to be correlated with pharyngeal airway shape and volume. This study used CBCT imaging to identify what, if any, effects two different treatment modalities for correcting Class II malocclusions have on the pharyngeal airway volume. This retrospective study consisted of two groups of Class II patients: 38 patients (15 females, 23 males) treated with the MARA and an Edgewise appliance and 32 patients treated with an Edgewise appliance and Class II elastics. Both pre and post treatment CBCT images (n=140) were analyzed using Dolphin3D© imaging software and a custom cephalometric analysis module. Analysis of the airway was done in three regions defined as 1) the nasopharynx (area superior and posterior to the posterior nasal spine), 2) the oropharynx (inferior to the PNS and superior to the epiglottis), and 3) the total airway volume (nasopharynx + oropharynx). ANOVA models were employed to simultaneously test variables for group differences (sex, treatment, sex + treatment). The results did not identify any significant in-treatment differences between the treatment groups with regard to the pharyngeal airway volume. It was concluded that the dentofacial treatment differences obtained with these two Class II correction methods were not enough to have a significant effect on the pharyngeal airway volume

Bone Cutting, Placement, and Cannibalism? Middle Preceramic Mortuary Patterns of Nanchoc, Northern Peru

Mortuary practices of the Middle Preceramic period (ca. 8500-4000 B.P.) are discussed for the Nanchoc region of the upper Zaña Valley, northern Peru. Careful breaking, cutting, and placement of human bones from adult males during the Las Pircas Phase (8500-6000 B.P. ) gave way to more haphazard breakage and discard during the subsequent Tierra Blanca Phase (6000-5000 B.P.). The evidence of cannibalism is considered. Bone breakage, cutting, and possibly cannibalism is believed to have been part of a broader process of ritualization that mitigated the spiritual danger of the transition from hunting-gathering to horticulture. Este trabajo discute las prácticas mortuorias del Período Precerámico Medio (ca. 8500 - 4000 A.P.) de la región Nanchoc del Valle superior de Zaña del norte de Perú. Rompimiento de huesos en forma cuidadosa, cortes y entierro de huesos de hombres adultos durante la Fase Las Pircas (8500 - 600 A.P.) da lugar a un quebramiento mas al azar de huesos y subsecuente descarte en la Fase Tierra Blanca (6000 - 5000 A. P.). Se considera la posibilidad de canibalismo. Las quebraduras de huesos, cortes y posiblemente el canibalismo podrían haber sido parte importante de un amplio proceso de rituales que mitigaban el peligro espiritual de la transición de los cazadores recolectores a la horticultura

The "Arauco State" against the spanish conquest: Ritual and socio-political structure of the araucano-mapuches in the Nahuelbuta valleys during the 16th and 17th centuries

Este artículo presenta evidencias arqueológicas y etnohistóricas que muestran la complejidad de la organización sociopolítica de las poblaciones que habitaban los valles que entrecruzan y circundan la cordillera de Nahuelbuta durante el siglo XVI y principios del siglo XVII, particularmente en el valle de Purén-Lumaco. La hipótesis que se sostiene es que la estructura sociopolítica, la densidad demográfica y las características económicas y culturales de las poblaciones de dicha área presentan una mayor complejidad y dimensiones superiores a lo que comúnmente se admite en la literatura arqueológica, histórica y antropológica. Las formas de organización sociopolíticas y los modos de asentamiento de las poblaciones araucano-mapuches de los siglos XVI y principios del siglo XVII tenderían a aproximarse, desde esta perspectiva, a modelos complejos característicos del mundo andino

ONDE ESTÃO OS REMANESCENTES ÓSSEOS HUMANOS DO FINAL DO PLEISTOCENO?

ONDE ESTÃO OS REMANESCENTES ÓSSEOS HUMANOS DO FINAL DO PLEISTOCENO