Factors influencing the plasticity and strength of lime-soil mixtures

Prepared as part of an investigation conducted by the Engineering Experiment Station, University of Illinois, in cooperation with the State of Illinois Division of Highways and the U.S. Bureau of Public Roads, Project IHR-76: Lime stabilization of soils for highway purposes.Cover title.Bibliography: p. 19-20

340 years of atmospheric circulation characteristics reconstructed from an eastern Antarctic Peninsula ice core

Copyright @ 2006 American Geophysical Union (AGU)Precipitation delivery mechanisms for Dolleman Island (DI), located off the east coast of the Antarctic Peninsula, are investigated using reanalysis and back trajectory data. The Southern Annular Mode (SAM) and ENSO are both shown to influence precipitation delivery and event size. Precipitation delivery variability is compared against the interannual variation of chemical data from two DI ice cores. Nitrate concentration in the cores is strongly linked with the ratio of easterly to westerly back trajectories arriving at DI, as described by a Cross-Peninsula Index (CPI) defined in this paper. This CPI is used subsequently to reconstruct the atmospheric circulation characteristics for the 340-year ice core record. The analysis highlights a period of increased easterlies during 1720–1780 and an increase in westerlies for 1950–1980, the latter concomitant with a positive SAM trend and western Peninsula warming. The reconstruction also reveals periods when polynyas may have been present in the Weddell Sea

Effects of word frequency and contextual predictability on sentence reading in aphasia: An eye movement analysis

Background: Mild reading difficulties are a pervasive symptom of aphasia. While much research in aphasia has been devoted to the study of single word reading, little is known about the process of (silent) sentence reading. Reading research in the non-brain-damaged population has benefited from the use of eye-tracking methodology, allowing inferences on cognitive processing without participants making an articulatory response. This body of research identified two factors, which strongly influence reading at the sentence level: word frequency and contextual predictability (influence of context). Aims: The main aim of this study was to investigate whether word frequency and contextual predictability influence sentence reading by people with aphasia (PWA), in parallel to that of neurologically healthy individuals (NHI). A second aim was to examine whether readers with aphasia show individual differences in the effects, and whether these are related to their underlying language profile. Methods & Procedures: Seventeen PWA and associated mild reading difficulties and 20 NHI took part in this study. Individuals with aphasia completed a range of language assessments. For the eye-tracking experiment, participants silently read sentences that included target words varying in word frequency and predictability while their eye movements were recorded. Comprehension accuracy, fixation durations, and the probability of first-pass fixations and first-pass regressions were measured. Outcomes & Results: Eye movements by both groups were significantly influenced by word frequency and predictability, but the predictability effect was stronger for the PWA than the neurologically healthy participants. Additionally, effects of word frequency and predictability were independent for the NHI, but the individuals with aphasia showed a more interactive pattern. Correlational analyses revealed (i) a significant relationship between lexical-semantic impairments and the word frequency effect score and (ii) a marginally significant association between the sentence comprehension skills and the predictability effect score. Conclusions: Consistent with compensatory processing theories, these findings indicate that decreased reading efficiency may trigger a more interactive reading strategy that aims to compensate for poorer reading by putting more emphasis on a sentence context, particularly for low-frequency words. For those individuals who have difficulties applying the strategy automatically, using a sentence context could be a beneficial strategy to focus on in reading intervention

Estimating the Effects of Part Size on Direct Laser Deposition Parameter Selection via a Thermal Resistance Network Approach

A mathematical model for heat transfer during the Directed Energy Deposition (DED) process is proposed. The model employs the thermal resistance network analogy and is developed to aid one in predicting part size effects on its temperature distribution during manufacture, and in how to compensate such effects via suitable process parameter selection. The model predicts a pseudo steady-state temperature response in the melt pool. The temperature variation along the heat affected zone of a thin-walled part is estimated while assuming deposition is occurring far from the substrate. Predicted melt pool and bulk part temperatures are validated against Laser Engineering Net Shaping (LENSTM) experimental data obtained via a dual-wavelength pyrometer and in-chamber infrared camera, respectively. Results demonstrate that the model may be used to predict an average melt pool temperature. Bulk, calculated temperature distribution needs to be further investigated to find a more suitable heat transfer coefficient surrounding the part.Mechanical Engineerin

Detection and characterization of a 500 μm dust emissivity excess in the Galactic plane using Herschel/Hi-GAL observations

Context. Past and recent observations have revealed unexpected variations in the far-infrared – millimeter (FIR-mm) dust emissivity in the interstellar medium. In the Herschel spectral range, those are often referred to as a 500 μm emission excess. Several dust emission models have been developed to interpret astrophysical data in the FIR-mm domain. However, these are commonly unable to fully reconcile theoretical predictions with observations. In contrast, the recently revised two level system (TLS) model, based on the disordered internal structure of amorphous dust grains, seems to provide a promising way of interpreting existing data. Aims. The newly available Herschel infrared GALactic (Hi-GAL) data, which covers most of the inner Milky Way, offers a unique opportunity to investigate possible variations in the dust emission properties both with wavelength and environment. The goal of our analysis is to constrain the internal structure of the largest dust grains on Galactic scales, in the framework of the TLS model. Methods. By combining the IRIS (Improved Reprocessing of the IRAS Survey) 100 μm with the Hi-GAL 160, 250, 350, and 500 μm data, we model the dust emission spectra in each pixel of the Hi-GAL maps, using both the TLS model and, for comparison, a single modified black-body fit. The effect of temperature mixing along the line of sight is investigated to test the robustness of our results. Results. We find a slight decrease in the dust temperature with distance from the Galactic center, confirming previous results. We also report the detection of a significant 500 μm emissivity excess in the peripheral regions of the plane (35° < |l| < 70°) of about 13–15% of the emissivity, which can reach up to 20% in some HII regions. We present the spatial distributions of the best-fit values for the two main parameters of the TLS model, i.e. the charge correlation length, lc, used to characterize the disordered charge distribution (DCD) part of the model, and the amplitude A of the TLS processes with respect to the DCD effect. These distributions illustrate the variations in the dust properties with environment, in particular the plausible existence of an overall gradient with distance to the Galactic center. A comparison with previous findings in the solar neighborhood shows that the local value of the excess is less than expected from the Galactic gradient observed here

Linearly polarized X-ray flares following short gamma-ray bursts

Soft X-ray flares were detected to follow the short-duration gamma-ray burst GRB 050724. The temporal properties of the flares suggest that they are likely due to the late time activity of the central engine. We argue that if short GRBs are generated through compact star mergers, as is supported by the recent observations, the jet powering the late X-ray flares must be launched via magnetic processes rather than via neutrino-antineutrino annihilations. As a result, the X-ray flares following short GRBs are expected to be linearly polarized. The argument may also apply to the X-ray flares following long GRBs. Future observations with the upcoming X-ray polarimeters will test this prediction.Comment: 4 pages (no figure), accepted for publication in ApJL, typos correcte

Mechanistic-Empirical (M-E) Design Implementation & Monitoring for Flexible Pavements: 2018 PROJECT SUMMARY

This document is a summary of the tasks performed for Project ICT-R27-149-1. Mechanistic-empirical (M-E)–based flexible pavement design concepts and procedures were previously developed in Illinois Cooperative Highway Research Program projects IHR-510, IHR-524, ICT- R28, and ICT-R27-060; and have been implemented by the Illinois Department of Transportation (IDOT). IDOT continues to support a variety of M-E flexible pavement analyses as well as design, implementation, and monitoring activities. The objective of Project ICT-R27-149-1 was for University of Illinois staff to continue to provide technical support and cooperate with IDOT in these activities. The cost savings (and probably reduced user delay time) from such designs will benefit IDOT, local roads agencies, and the travelling public.IDOT-R27-149-1Ope

Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) nitric acid (HNO&lt;sub&gt;3&lt;/sub&gt;) and nitrogen dioxide (NO&lt;sub&gt;2&lt;/sub&gt;) profiles and distributions of 1978/1979 are described after their processing with an updated, Version 6 (V6) algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO&lt;sub&gt;3&lt;/sub&gt; profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5) profiles, except in the upper stratosphere where the interfering effects of CO&lt;sub&gt;2&lt;/sub&gt; are accounted for better with V6. The accuracy of the retrieved V6 NO&lt;sub&gt;2&lt;/sub&gt; is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO&lt;sub&gt;3&lt;/sub&gt;/NO&lt;sub&gt;2&lt;/sub&gt; ratio, day-to-night NO&lt;sub&gt;2&lt;/sub&gt; ratio, and with estimates of the production of NO&lt;sub&gt;2&lt;/sub&gt; in the mesosphere and its descent to the upper stratosphere during polar night. In particular, the findings for middle and upper stratospheric NO&lt;sub&gt;2&lt;/sub&gt; should also be more compatible with those obtained from more recent satellite sensors because the effects of the spin-splitting of the NO&lt;sub&gt;2&lt;/sub&gt; lines are accounted for now with the LIMS V6 algorithm. The improved precisions and more frequent retrievals of the LIMS profiles along their orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be studied quantitatively throughout the stratosphere with the LIMS V6 data

Customers as decision-makers: strategic environmental assessment in the private sector

Despite its diversification and global spread, strategic environmental assessment (SEA) remains limited mainly to activities characterised by well-defined planning processes, typically within the public sector. This article explores the possible application of SEA within certain private-sector contexts where higher-level strategy-making itself is inherently weaker and development is often piecemeal and reactive. The possible adaptation of SEA to the preparation of a strategic document by a particular industrial concern in the UK is examined: this draws attention to the multi-actor nature of development processes within the industry. This leads to the suggestion that SEA in this setting should be thought of as a form of environmental advocacy oriented towards industrial customers, who are understood as sharing a decision-making role in infrastructure development.</p