Structural changes in latosols of the cerrado region: I - relationships between soil physical properties and least limiting water range

The agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected from the B horizons of five oxidic Latosols representing the textural variability of the Latosols of the Cerrado biome. LLWR and other soil physical properties were determined at various soil compaction degrees induced by uniaxial compression. Soil compaction caused effects varying from enhanced plant growth due to higher water retention, to severe restriction of edaphic functions. Also, inverse relationships were observed between clay content and bulk density values (Bd) under different structural conditions. Bd values corresponding to critical soil macroporosity (BdcMAC) were more restrictive to a sustainable use of the studied Latosols than the critical Bd corresponding to LLWR (BdcLLWR). The high tolerable compression potential of these oxidic Latosols was related to the high aeration porosity associated to the granular structure.

Safety and Mobility Impacts of Winter Weather – Phase I, August 2011

Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. Phase I of this project investigated opportunities for improving traffic safety on state-maintained roads in Iowa during winter weather conditions. The primary objective was to develop several preliminary means for the Iowa Department of Transportation (DOT) to identify locations of possible interest systematically with respect to winter weather-related safety performance based on crash history. Specifically, metrics were developed to assist in identifying possible habitual, winter weather-related crash sites on state-maintained rural highways in Iowa. In addition, the current state of practice, for both domestic and international highway agency practices, regarding integration of traffic safety- and mobility-related data in winter maintenance activities and performance measures were investigated. This investigation also included previous research efforts. Finally, a preliminary work plan, focusing on systematic use of safety-related data in support of winter maintenance activities and site evaluation, was prepared.

Analysis of the role of mobility-lifetime products in the performance of amorphous silicon p-i-n solar cells

An analytical model of an amorphous silicon p-i-n solar cell is presented to describe its photovoltaic behavior under short-circuit conditions. It has been developed from the analysis of numerical simulation results. These results reproduce the experimental illumination dependence of short-circuit resistance, which is the reciprocal slope of the I(V) curve at the short-circuit point. The recombination rate profiles show that recombination in the regions of charged defects near the p-i and i-n interfaces should not be overlooked. Based on the interpretation of the numerical solutions, we deduce analytical expressions for the recombination current and short-circuit resistance. These expressions are given as a function of an effective ¿¿ product, which depends on the intensity of illumination. We also study the effect of surface recombination with simple expressions that describe its influence on current loss and short-circuit resistance.

Syntaxonomic conspectus of the vegetation of Catalonia and Andorra. I: Hygrophilous herbaceous communities.

The first part of a general survey of the vegetation of Catalonia andAndorra, this paper reports all the phytocoenological associations and subassociations recorded in this area. For each community, we provide the correct name and usual synonyms, its typification (where appropriate), all the references including relevés, and the most outstanding features of its structure, species composition, ecology, distribution and diversity. Moreover, associations and subassociations are ordered appropriately in a syntaxonomic scheme. Syntaxonomic ranks are considered in a fairly broad, conservative sense. This classification established 101 associations, which correspond to the classes Lemnetea, Zosteretea, Potametea, Littorelletea, Montio-Cardaminetea, Phragmiti-Magnocaricetea, Scheuchzerio-Caricetea, Isoeto-Nanojuncetea and Molinio-Arrhenatheretea.

Ag Decision Maker, August 2004, Vol. 8, no. 10

A Business Newsletter for Agriculture

Evaluation of Steel Bridges, Volumes I & II, TR-493, 2007

This report is divided into two volumes. This volume (Volume I) summarizes a structural health monitoring (SHM) system that was developed for the Iowa DOT to remotely and continuously monitor fatigue critical bridges (FCB) to aid in the detection of crack formation. The developed FCB SHM system enables bridge owners to remotely monitor FCB for gradual or sudden damage formation. The SHM system utilizes fiber bragg grating (FBG) fiber optic sensors (FOSs) to measure strains at critical locations. The strain-based SHM system is trained with measured performance data to identify typical bridge response when subjected to ambient traffic loads, and that knowledge is used to evaluate newly collected data. At specified intervals, the SHM system autonomously generates evaluation reports that summarize the current behavior of the bridge. The evaluation reports are collected and distributed to the bridge owner for interpretation and decision making. Volume II summarizes the development and demonstration of an autonomous, continuous SHM system that can be used to monitor typical girder bridges. The developed SHM system can be grouped into two main categories: an office component and a field component. The office component is a structural analysis software program that can be used to generate thresholds which are used for identifying isolated events. The field component includes hardware and field monitoring software which performs data processing and evaluation. The hardware system consists of sensors, data acquisition equipment, and a communication system backbone. The field monitoring software has been developed such that, once started, it will operate autonomously with minimal user interaction. In general, the SHM system features two key uses. First, the system can be integrated into an active bridge management system that tracks usage and structural changes. Second, the system helps owners to identify damage and deterioration.

Revenue Estimating Conference: Estimate of General Fund Receipts, October 10, 2003

The past actual tax receipts and future estimates of the General Fund used by the Revenue Estimating Conference to project incoming revenue to be used in future state budgeting.

Recycling of Asphalt Concrete From I-80 in Cass County, HR-1011, 1978

Approximately 40,000 tons of deteriorated asphalt concrete has been removed from Interstate 80 in Cass County and stockpiled. Laboratory tests indicate that this material has considerable value when upgraded with new aggregate and asphalt cement. This report documents the procedures used and results obtained on an experimental recycling project. It was demonstrated that present drum mixing-recycling equipment and procedures can be used to utilize this material with satisfactory results. Laboratory analyses of material components and mixtures were performed; these analyses indicate mixture can be produced that is uniform, stable, and very closely resembles mixture produced with all virgin material. A 1700 foot long test section was constructed on US 169 in Kossuth County wherein salvaged asphalt concrete from I-80 in Cass County was utilized. The salvaged mix was blended with virgin aggregate and recycled through a modified drum mixing plant, the reprocessed mixture was satisfactorily placed 1 1/2 inches thick as a resurfacing course on an old PCC pavement. An inspection of the test section was made in December of 1978 to evaluate the performance after one full year of service. There was no evidence of rutting or shoving from traffic. The surface does, however, have a very dry and somewhat ravelled appearance. This can be related to a low asphalt content in the mix and some temperature control problems which were difficult to get fully corrected on such a short project and with a short supply of readily available materials.

Instrumentation of Paver Vibrators, MLR-95-10, 1999

Premature deterioration of Portland Cement Concrete (PCC) pavements led to investigations for causes of the concrete failures. Evidence of parallel longitudinal cracks in deteriorating pavements, with crack spacings similar to paver vibrator spacings, made it clear that the vibrators were related to the cause for deterioration. After a number of field trips observing paving operations and measuring vibrator frequencies, it soon became clear that the paver vibrators were, in many cases, not running in compliance with the Iowa DOT specification. The specified frequency was from 5000 to 8000 revolutions per minute (rpm). The pavers visited did not have a monitoring system to give a continuous frequency readout for any of it's vibrators. Occasionally, during a paving operation, frequency readings were taken on some vibrators with a hand held tachometer. However, that degree of monitoring was found to be far from providing the quality of information and control necessary to maintain compliance to the Iowa DOT specification. A paver vibrator monitoring system, which would operate continuously while paving and cover all vibrators, was determined to be essential. The output must be visible to the paver operator and inspector at all times.

Evaluación de la educación emocional en el ciclo medio de Educación Primaria

El principal propósito de la educación consiste en favorecer el desarrollo integral de la persona, lo cual implica atender el aspecto cognitivo y afectivo. Tradicionalmente, se han priorizado sólo los contenidos cognitivos por este motivo queremos incidir sobre los afectos. El objetivo general de este trabajo de investigación que presentamos consiste en aplicar y evaluar un Programa de Educación Emocional (PEEP), integrado dentro del currículum de Primaria de ciclo medio que ayude a prevenir los efectos nocivos de las emociones negativas y facilite la relación consigo mismo y con los demás. Objetivo general que se constatara a partir de cuatro criterios: conseguir un mejor conocimiento de las propias emociones y de las emociones de los demás, desarrollar estrategias de regulación emocional, mejorar la autoestima, aprender habilidades de vida y socioemocionales. Pues, la finalidad es intervenir en la mejora de la educación emocional de los alumnos entre los 8 y los 10 años, en total 510 alumnos de los cuales 104 formaron la muestra de investigación. Fueron divididos en dos grupos el grupo experimental y el grupo control, ambos constituían una muestra homogénea y estadísticamente comparable por lo que podíamos plantearnos una intervención y valorar su incidencia. Los resultados indican que mejora el nivel de Educación Emocional (EE) de estos alumnos con un nivel de significación de p= 0,001. A partir de este momento, podemos concretar que los resultados conseguidos por los alumnos que han seguido la aplicación del programa mejoran significativamente. Este resultado, nos permite afirmar que el uso intencional del programa de educación emocional para mejorar el ámbito afectivo ha incidido positivamente en el proceso de aprendizaje de los alumnos. Sin embargo consideramos esencial llevar a cabo una formación y posterior evaluación del profesorado en EE, como paso previo necesario para una aplicación óptima del programa.

Elaborated Literary Violence: Genre and Ideology of the Two Stories I Sam 22,6-23 and II Sam 21,1-14

The present article focuses on two stories dealing with acts of big blood shed. I Sam 22,6-23 relates the massacre of the priests of Nob; II Sam 21,1-14 is about the execution of seven descendents of Saul, as atonement for Saul's attempt to exterminate the Gibeonites. Most researchers consider both stories or at least certain parts of them old.1 For both stories few verses are regarded as secondary. In this paper I try to reassess the analysis of these stories and will point to indices favoring a late date of origin for both of them. They concern the language in use, intertextual connections and particular motifs. A further indication consists in the fact that the reported events of the stories lack significant resonance in the corpus of the Hebrew Bible. There are only two texts, I Sam 2,33 and Ps 52,2, which allude or refer to I Sam 22,6-23.With regard to the importance of the related events and acts this silence in the Biblical context is astonishing. Interestingly, also in the Book of Chronicles one does not find any allusions to these stories. This raises the question whether the latter were composed after the formation of the book of Chronicles.