Effect of a hydrophobic layer on the upward movement of water under freezing conditions

Frost heave is the process in which wet soil with an available water source undergoes freezing, deformation, and upward movement of the soil surface. This deformation can cause damage to engineering structures such as pavements and shallow foundations. Investigating ways to minimize frost heave by reducing water flow in the system is beneficial. A possible way to reduce the water movement is to add a hydrophobic layer of soil between the water source (e.g. water table) and the freezing surface. The objective of this study was to examine the effect of a hydrophobic treated soil layer on water movement and temperature changes in a soil profile under surface freezing conditions. A vertical soil cell set-up including a column-within-a-column design was used to establish one-dimensional vertical heat flow between a surface boundary condition below freezing and an ambient boundary temperature condition at the bottom of the cell. A constant water table was established at the bottom of the column to provide a water source for water uptake due to freezing. Water uptake in soil cells without a hydrophobic layer was found to be greater by one order of magnitude than water uptake in soil cells with a hydrophobic layer. Soil with a hydrophobic layer had less accumulation of ice and froze to greater depths than soil without a hydrophobic layer. A hydrophobic soil layer can reduce water movement in freezing soil

Southeast Michigan Local Road Concrete Pavement Durability Study

Counties and cities in Southeast Michigan have used concrete pavements for nearly 100 years to provide long-lasting, durable streets and roads. Issues of concrete durability have arisen with some of the pavements built after 1990. In order to evaluate the causes of spalling and other deterioration methods, the National Concrete Pavement Technology Center (CP Tech Center) was asked to study the concrete from a number of the pavements, evaluate the causes of the distress, and offer recommendations for improvements. Of particular concern are the roles of coarse aggregate type (limestone or blast furnace slag), alkali-silica reactivity (ASR), and the air entrainment system in the hardened concrete on the joint deterioration distresses that are being observed

Phase I (Laboratory): Investigation of Soil Stabilization Alternatives—Texas SH 130

Portland cement, hydrated lime, slag, class C and F fly ash, and a few nontraditional chemical stabilizers were evaluated in the laboratory for their effectiveness in improving strength and reducing swell potential of high-plasticity clay materials sampled at the proposed SH 130 project site in Texas. In addition to high plasticity index values, soils in the proposed construction area reportedly contain variable amounts of sulfate content that may lead to deleterious expansion due to secondary mineral growth. Over 900 test specimens from the project site were prepared and tested. The goal of the laboratory phase of this project was to provide recommendations for conducting field test strip evaluations of the select portland cement stabilizers or combinations of Portland cement and other stabilizers. Unconfined compressive strength, volume change, pH, soil classification, X-ray analysis, and scanning electron microscopy methods were used in this analysis. An unconfined compressive strength of 100 psi, a maximum volume change of 2%, and a decrease in the plasticity index were used as evaluation criteria for determining suitable stabilizers for field trials. The following cement-based stabilization mixtures would meet the laboratory-established criteria: 6% Cement Type I/II or Type V, 4% Cement Type I/II + 4% Fly ash Class C, 4% Cement Type I/II + 4% Fly ash Class F, and 3% Cement Type I/II + 3% Fly ash Class C or F. Further evaluation by field testing, with several months of evaluation including in-situ testing, sampling, and in-ground instrumentation monitoring, is recommended for Phase II. A testing plan for evaluation is presented in this report. The outcome of the field investigation would be conclusive performance results for the recommended stabilizers in terms of strength, stiffness, and volume change. It is further recommended that the stabilization construction methods be evaluated as part of the field evaluation. This would specifically include variable mixing rates and use of intelligent compaction technology with GPS mapping capabilities

Determining the structural dynamics of MMP-3/TIMP complex from NMR relaxation

Abstract only availableMMP-3, or Stromelysin 1, is an proteolytic enzyme of the extracellular matrix that is involved in the repair of wounds. It is implicated in inflammation and cartilage damage and inflammation in rheumatoid arthritis and damage to the blood-brain barrier immediately after stroke. While a natural inhibitor does exist, it stops all processes, good and bad. MMP-3 must be selectively inhibited, and for this reason, we must understand how Tissue Inhibitor of Metalloproteinases (TIMP) inhibits MMP-3. Using NMR spectroscopy, the chemical shift of the 15N and 1H atoms, as well as the 15N NMR relaxation data (R1;, R&sub2;, and heteronuclear NOE) of the MMP-3 protein was recorded. Using NMRpipe, this data was converted into a spectrum, showing the contoured peaks. Using the NMR program Sparky, the relaxation data were fitted, and converted into a relaxation rate constant for each residue. For more accurate results, the data was filtered twice: coarse and fine. After coarse filtering, it was realized that the R2 data were collected at different a frequency than the R1 data. This renders the data less compatible. Preparation of new samples to be done at the correct frequencies will be completed sometime in the near future. Once this is accomplished, the new relaxation data for R2 can be calculated, and the dynamics of the MMP-3/TIMP complex can be calculated accurately.Missouri Academy at Northwest Missouri State Universit

Iowa DOT Intelligent Compaction Research and Implementation—Phase I

The Iowa Department of Transportation Intelligent Compaction Research and Implementation was initiated in summer 2009. Three field demonstration projects were conducted in Iowa as part of Phase I of this research program to evaluate three different IC measurement technologies: (1) machine drive power (MDP) measurement technology on Caterpillar CP56 padfoot roller, (2) continuous compaction value (CCV) technology on Sakai SW880 dual vibratory smooth drum asphalt roller, and (3) compaction meter value (CMV) technology on Volvo SD116DX smooth drum vibratory roller. The main objectives of the project include: evaluating the effectiveness of the IC measurement values (IC-MVs) in assessing the compaction quality of cohesive subgrade materials, granular base/subbase materials, and HMA materials, developing project specific correlations between IC-MVs and various conventionally used in-situ point measurements in earthwork quality control (QC) and quality assurance (QA) practice and HMA construction, evaluating the advantages of using the IC technology for production compaction operations, obtaining data to evaluate future IC specifications, and developing content for future educational and training materials for Iowa DOT and contractor personnel for effective implementation of the technology in to earthwork and HMA construction practice. This research report presents results obtained from the three demonstration projects along with an overview of the different IC technologies and various QC/QA test methods. Statistical regression analysis was performed to evaluate correlations between IC-MVs and various in-situ test measurements (e.g., dry unit weight, moisture content, modulus, California bearing ratio, temperature (for HMA)). Comparatively, modulus was better correlated with IC-MVs compared to dry unit weight. Geostatistical analysis methods were used to assess “uniformity” of the spatially referenced IC measurements. Results from this study were used to develop special provision specifications as part of Phase II research program

Nutrient Management Planning in Iowa

Nutrient management planning in Iowa can be a complex process. The degree of planning is dependent on the need for one or more different types of management plans to serve the different requirements of state agencies. While the objectives of the plans are the same, sound nutrient management and resource protection, the methods of planning are quite different. Producers, their technical advisors, and agency staff are often confused as to what regulations must be met and what practices must be employed to meet the various goals of required and voluntary plans. The goal of this workshop is to present two types of nutrient plans used in Iowa and document differences and similarities in the nutrient management plans

Geotechnical Solutions for Soil Improvement, Rapid Embankment Construction, and Stabilization of the Pavement Working Platform, Performance Assessment of Lime and Fly Ash Chemically Treated Subgrade

Chemical treatment and stabilization of subgrades is a long-standing method to construct working platforms and improve the support conditions for pavement systems. Lime, cement, and fly ash are common chemical stabilization agents and are often incorporated with subgrade materials to improve volumetric stability, freeze-thaw performance, and/or subgrade stiffness. Although laboratory test methods and design procedures are relatively well established, the long-term (5+ years) field performance characteristics of treated or stabilized subgrades is poorly documented and was the focus of this study. The main objectives of this project were as follows: Document engineering properties (in situ strength/stiffness) and mineralogical/micro-structural characteristics of chemical stabilized subgrades, in comparison with natural subgrades at the same sites Understand factors that contribute to long-term engineering behavior of stabilized subgrade Nine test sections were selected to assess engineering properties of old stabilized subgrades in Texas, Oklahoma, and Kansas. The selection of the test sites was based on the type of subgrade, availability of old construction records, and age. Subgrades at six of these sites were stabilized with lime and the other three with fly ash. Eight of these test sites were more than 10 years old, and one test site was about 5 years old. Eight sites consisted of flexible pavement supported on base and stabilized subgrade or just stabilized subgrade, and one site consisted of concrete pavement supported on cement treated base and stabilized subgrade Results from this study provide new information that should be of great interest to pavement designers dealing with selection of design parameters for chemically stabilized subgrade layers

Isolating Processing Factors in Negative Island Contexts *

Introduction The phenomenon referred to as negative islands was originally observed by (1) a. Which project didn't the intern complete __ conscientiously? b. *How didn't the intern complete the project __? A number of proposals have been made in the theoretical linguistics literature that account for the difference between (1a) and (1b) in terms of global constraints operating within the grammar. Building on previous findings in the psycholinguistics literature, we used acceptability judgment measures to provide a new window into our understanding of negative islands. On the basis of results from two such studies, we argue that negative islands are not a unitary phenomenon due to a single global grammatical constraint, but rather the by-product of the simultaneous co-occurrence of different processing factors. The paper is structured as follows. In section 2, we show that alongside the global constraints proposed in existing accounts of negative islands, there is abundant evidence in the psycholinguistics literature that each of the individual factors that figure into negative islands -namely negation, extraction, and referentiality -incurs its own processing cost. The results from the acceptability judgment studies reported in section 3 demonstrate the importance of taking these individual factors into consideration when analyzing negative islands. In Experiment 1, we investigate the effects of the factors negation and extraction, and in Experiment 2 we additionally manipulate the factor of referentiality. In section 4, we discuss the results of these experiments and sugges

Progress, Challenges, and New Opportunities for the Prevention of Mother-to-Child Transmission of HIV Under the US Presidentʼs Emergency Plan for AIDS Relief

In June 2011, the Joint United Nations Programme on HIV/AIDS, the US President’s Emergency Plan for AIDS Relief (PEPFAR), and other collaborators outlined a transformative plan to virtually eliminate pediatric AIDS worldwide. The ambitious targets of this initiative included a 90% reduction in new pediatric HIV infections and a 50% reduction in HIV-related maternal mortality—all by 2015. PEPFAR has made an unprecedented commitment to the expansion and improvement of prevention of mother-to-child HIV transmission (PMTCT) services globally and is expected to play a critical role in reaching the virtual elimination target. To date, PEPFAR has been instrumental in the success of many national programs, including expanded coverage of PMTCT services, an enhanced continuum of care between PMTCT and HIV care and treatment, provision of more efficacious regimens for antiretroviral prophylaxis, design of innovative but simplified PMTCT approaches, and development of new strategies to evaluate program effectiveness. These accomplishments have been made through collaborative efforts with host governments, United Nations agencies, other donors (eg, the Global Fund for AIDS, Tuberculosis, and Malaria), nongovernmental organizations, and private sector partners. To successfully meet the ambitious global targets to prevent new infant HIV infections, PEPFAR must continue to leverage the existing PMTCT platform, while developing innovative approaches to rapidly expand quality HIV services. PEPFAR must also carefully integrate PMTCT into the broader combination prevention agenda for HIV, so that real progress can be made toward an “AIDS-free generation” worldwide