Heat flow and geothermal potential of Kansas

Temperature, thermal-conductivity measurements, and heat-flow values are presented for four holes in Kansas originally drilled for cooperative water-resources investigations by the Kansas Geological Survey and the U.S. Geological Survey. These holes cut most of the sedimentary section and were cased and allowed to reach temperature equilibrium. Several types of geophysical logs were run for these holes. Temperature data from an additional five wells also are presented. Temperature gradients in the sedimentary section vary over a large range (over 4:1), and significantly different temperatures occur at the same depth in different portions of the state. Temperatures as high as 34°C (93°F) occur at a depth of 500 m (1,650 ft) in the south-central portion of the state but are 28°C (82°F) or lower at that depth in other parts of the state. In addition to cuttings measurements, thermal conductivities were estimated from geophysical well-log parameters; useful results suggest more use of the technique in the future. With these results, geophysical well logs can be used to predict temperatures as a function of depth in areas for which no temperatures are available if heat flow is assumed. The extreme variation in gradients observed in the holes occurs because of the large contrast in thermal-conductivity values. Shale thermal-conductivity values appear to have been overestimated in the past; Paleozoic shales in Kansas have thermal-conductivity values of approximately 1.18 ± 0.03 Wm-1K-1. Conversely, evaporite and dolomite units have thermal conductivities of over 4 Wm-1K-1. In spite of the large variations of gradient, the heat-flow values throughout the holes do not vary more than 10%, and any water-flow effects which might be present from the lateral motion on any of the aquifers are less than 10%. The best estimates for heat flow in the four holes come from carbonate units below the base of the Pennsylvanian and range in value from 48 mWm-2 to 62 mWm-2. Two of the holes were drilled to the basement, and correlation of the heat flow with basement radioactivity suggests that the heat-flow/heat-production line postulated for the midcontinent by Roy, Blackwell, and Birch (1968) applies to these data. Because of the low thermal conductivity of the shales, the radiogenic-pluton concept should apply to the midcontinent. Thus, if very radioactive plutons can be identified, much higher temperatures may occur in the sedimentary section than have been thought possible in the past. However, the past overestimation of the shale-conductivity values suggests that some previous high heat-flow values in the midcontinent probably are not correct, and the high gradients are due instead to normal heat flow and very low thermal-conductivity values. In spite of the presence of-low thermal-conductivity values in the midcontinent region, significant use could be made of geothermal energy in Kansas for space heating, thermal assistance, and heat-pump applications because the temperatures in the sedimentary section in much of Kansas are in excess of 40°C (104°F)

Heat flow and geothermal potential of Kansas

Temperature, thermal-conductivity measurements, and heat-flow values are presented for four holes in Kansas originally drilled for cooperative water-resources investigations by the Kansas Geological Survey and the U.S. Geological Survey. These holes cut most of the sedimentary section and were cased and allowed to reach temperature equilibrium. Several types of geophysical logs were run for these holes. Temperature data from an additional five wells also are presented. Temperature gradients in the sedimentary section vary over a large range (over 4:1), and significantly different temperatures occur at the same depth in different portions of the state. Temperatures as high as 34°C (93°F) occur at a depth of 500 m (1,650 ft) in the south-central portion of the state but are 28°C (82°F) or lower at that depth in other parts of the state. In addition to cuttings measurements, thermal conductivities were estimated from geophysical well-log parameters; useful results suggest more use of the technique in the future. With these results, geophysical well logs can be used to predict temperatures as a function of depth in areas for which no temperatures are available if heat flow is assumed. The extreme variation in gradients observed in the holes occurs because of the large contrast in thermal-conductivity values. Shale thermal-conductivity values appear to have been overestimated in the past; Paleozoic shales in Kansas have thermal-conductivity values of approximately 1.18 ± 0.03 Wm-1K-1. Conversely, evaporite and dolomite units have thermal conductivities of over 4 Wm-1K-1. In spite of the large variations of gradient, the heat-flow values throughout the holes do not vary more than 10%, and any water-flow effects which might be present from the lateral motion on any of the aquifers are less than 10%. The best estimates for heat flow in the four holes come from carbonate units below the base of the Pennsylvanian and range in value from 48 mWm-2 to 62 mWm-2. Two of the holes were drilled to the basement, and correlation of the heat flow with basement radioactivity suggests that the heat-flow/heat-production line postulated for the midcontinent by Roy, Blackwell, and Birch (1968) applies to these data. Because of the low thermal conductivity of the shales, the radiogenic-pluton concept should apply to the midcontinent. Thus, if very radioactive plutons can be identified, much higher temperatures may occur in the sedimentary section than have been thought possible in the past. However, the past overestimation of the shale-conductivity values suggests that some previous high heat-flow values in the midcontinent probably are not correct, and the high gradients are due instead to normal heat flow and very low thermal-conductivity values. In spite of the presence of-low thermal-conductivity values in the midcontinent region, significant use could be made of geothermal energy in Kansas for space heating, thermal assistance, and heat-pump applications because the temperatures in the sedimentary section in much of Kansas are in excess of 40°C (104°F)

You Can\u27t Have It All: Faculty and Student Priorities in the Online Classroom

While potential teaching activities in the online classroom are unlimited, an instructor’s teaching time is not. As such, it is essential that online instructors prioritize limited time to instructional strategies that have the greatest impact on student learning. A survey of 413 faculty and 2386 students examined faculty and student perceptions about instructional components or strategies that have greatest impact on student learning in the online classroom. Findings revealed significant differences in faculty and student perceptions with faculty giving the highest value ratings to non-instructor generated content and students prioritizing text-based instructional content (regardless of source). Overall, faculty tended to place more value on instructional components compared to students. Students rated faculty interaction and feedback as the most valuable component of their online learning experience. Findings explore how institutions can utilize teaching supplements to support faculty’s desire to provide content so that instructional time can focus on interaction and feedback

Rotavirus genetic diversity, disease association, and temporal change in hospitalized rural Kenyan children

Background. The effectiveness of rotavirus vaccines will be dependent on the immunity conferred against prevalent and emergent variants causing severe diarrheal disease. Longitudinal surveillance of disease-causing strains is a prerequisite to intervention. Methods. Molecular characterization was conducted on rotavirus-positive stool samples from children admitted with diarrhea to a rural district hospital during 2002-2004. Extracted viral RNA was separated by polyacrylamide gel electrophoresis, and rotavirus VP4 (P types) and VP7 (G types) specificities were determined. Results. Among 558 investigated cases, the predominant genotype was P[8]G1 (42%), followed by P[8]G9 (15%), P[4]G8 (7%), P[6]G8 (6%), and P[8]G8 (4%), with 10% mixed strains. Overall, there were 6 different P types and 7 G types. No association was identified between genotype and child age, sex, or severity of diarrhea. The P and G genotypes and polyacrylamide gel electropherotypes showed significant temporal variation in frequency: P[8]G1 decreased from 51% (95% confidence interval [CI], 43%-58%) in 2002 to 30% (95% CI, 24%-37%) in 2004, and P[4]G8 increased from 2% (95% CI, 0%-5%) in 2002 to 13% (95% CI, 9%-19%). Quarterly data revealed seasonally endemic and emergence and/or decay patterns. Conclusions. Our study of rotavirus strains causing severe diarrhea in rural Kenyan children showed a predominance of P[8]G1 and confirms the importance of G8 and G9 strains in sub-Saharan Africa. Considerable genetic diversity of rotavirus strains was observed, including substantial mixed and unusual types, coupled with significant temporal strain variation and emergence. These results warn of variable vaccine efficacy and the need for long-term surveillance of circulating rotavirus genotypes

Política de álgebra universal I, acesso, e desigualdade: Resultados de uma pesquisa nacional

Many in the US view algebra as a gatekeeper to advanced study of mathematics, and increasing enrollment in algebra courses as a strategy to address unequal access to educational opportunity. As a result, universal enrollment policies, which require all students to complete Algebra I by grade 8 or 9, have garnered attention in school districts or states. Based on a view that school districts are the primary implementers of state and national policy in the US, this study surveyed a nationally representative sample of districts to investigate the prevalence of such policies and their relationship to algebra enrollment. Districts reported substantial increases in Algebra I enrollments in eighth grade, although ninth grade remains the most common year students enroll. Only 26% of districts reported having universal enrollment policies; in these districts, linear regression indicated that an association with higher eighth grade Algebra I enrollment was moderated by poverty level (measured by FRL). As a result, universal policies, while decreasing within-district disparities, may increase disparities between districts. These disparities may be explained by maximally maintained inequality (Raftery Hout, 1993) and effectively maintained inequality theories (Lucas, 2001), which posit that more affluent groups take deliberate action to perpetuate inequalities.Muchas personas en EEUU ven la álgebra como un portero para el estudio de matemáticas avanzadas y más inscripciones en cursos de álgebra como una estrategia para abordar el acceso desigual a las oportunidades educativas. La álgebra I en le nivel 8 o 9 se ha prestado atención a los distritos o estados escolares. En base a una visión de que los distritos escolares son los principales implementadores de la política estadual y nacional en los Estados Unidos, este estudio investigó una muestra de distritos para investigar la prevalencia de dichas políticas y su relación con la matrícula de álgebra. Los distritos reportaron aumentos sustanciales en las inscripciones de Álgebra I en le nivel 8, aunque la matrícula de le nivel 9 es más común. Sólo el 26% de los distritos relataron tener políticas universales de matrícula y regresión lineal indicaron que una asociación con inscripción superior en álgebra I de le nivel 8 fue moderada por el nivel de pobreza en esos distritos. Como resultado, al disminuir las disparidades dentro del distrito, las políticas universales pueden aumentar las disparidades entre los distritos. Esas disparidades pueden ser explicadas por la desigualdad máxima mantenida (Raftery Hout, 1993) y teorías de desigualdad efectivamente mantenidas (Lucas, 2001), que argumentan que grupos más afluentes toman acciones deliberadas para perpetuar las desigualdades.Muchas pessoas em EUA ven a álgebra como um portero para o estudo de matemáticas avançadas e mais inscrições em cursos de álgebra como uma estratégia para abordar o acesso desigual às oportunidades educativas. A álgebra I en le nivel 8 o 9 se ha prestado atenção a distritos ou estados escolares. Na base de uma visão de que os distritos escolares são os principais implementadores da política estadual e nacional nos Estados Unidos, este estudo investigou uma amostra de distritos para investigar a prevalência de políticas e sua relação com a matrícula de álgebra. Os distritos reportaram aumentos substanciales em inscrições de Álgebra I en le nivel 8, embora a matrícula do nível 9 es más común. Apenas os 26% dos distritos relataram ter políticas universais de matrícula e regresso lineal indicando que é uma associação com inscrição superior em álgebra I do nível 8 foi moderada pelo nível de propriedade de seus imigrantes. Como resultado, al disminuir as disparidades dentro do distrito, as políticas universais podem aumentar as disparidades entre os distritos. Estudo das expectativas para a desigualdade máxima da manutenção (Raftery Hout, 1993) e teorias de desigualdad efetivamente mantenidas (Lucas, 2001), que argumentan que grupos mais afluentes toman acciones deliberadas para perpetuar las desigualdades

Evaluation of the AGDISP ground boom spray drift model

AGDISP is a well-established spray drift model that has been validated for aerial spraying of forests. Recently a prototypical ground boom option has been added to AGDISP. This was evaluated in the current study by collecting data from spray trials over a grass sward using a ground boom sprayer and representative application parameters. Spray solutions were made up of water, sticker adjuvant and a metal cation, which was changed for each spray application. Deposition from spray drift was measured by analyses of the cation deposits on artificial targets (plastic tapes) placed on the grass surface. Measured deposition was compared with profiles calculated using AGDISP. AGDISP overpredicted deposition from spray drift by a factor of 3.5-100 outside the spray block. Possible reasons for these discrepancies are given. Options are to improve measured deposition and the algorithms for the deposition on the downwind swath of the spray block and evaporation of droplets