bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerated Sulfate Attack on Concrete in a Hot Climate
Authors: Wafa FF 
Published: January 2010

Abstract
An accelerated experimental investigation was conducted to study the effect of high sulfate concentration on concrete compressive strength. The effect of sulfate exposure on concrete compressive strength was evaluated by immersing concrete specimens (100-mm cubes) in a 10% magnesium-sulfate solution. The variable parameters were the type of cement, mixture proportions, curing period, and period of sulfate attack. Test results showed that the use of a high W-C ratio with Type I cement produced weak concrete with a loss of compressive strength up to 50% after 15 months of sulfate exposure. Using a rich mixture with Type V cement and a low W-C ratio produced dense impermeable concrete that showed no losses of strength even after 15 months of sulfate exposure in a hot humid environment.
Construction Materials Made with Coal Combustion By-Products
Authors: Wei L , Naik TR , Golden DM 
Published: January 2010

Abstract
A research program at the Center for By-Products Utilization, University of Wisconsin-Milwaukee, is being conducted to develop new low-cost construction materials primarily using coal combustion by-products. This paper reports results of research performed to develop concrete mixture proportions information using fly ash and bottom ash in masonry products. The influence of different types, amounts, and sources of ash on compressive strength and bulk density of concrete are given in this paper. The influence of curing temperature as well as using bottom ash as a replacement of natural aggregates is also reported. It is concluded that low-cost construction materials can be reliably developed using coal combustion by-products with potentially large savings to producers and consumers.
Effect of Curing on Shrinkage and Expansion of Surface Repair Mortars
Authors: Durand B , Mirza J 
Published: January 2010

Abstract
Hydro-Québec has undertaken a major study on the evaluation of repair materials for concrete surfaces damaged by erosion. Shrinkage-expansion and compressive tests, among others, were carried out on 36 different products: 12 cementitious mortars and grouts, eight cement-based mortars containing styrene-butadiene rubber (SBR), four cement-based mortars containing acrylics, and 12 epoxy mortars. For each mix, four 25 by 25 by 275-mm bars and six 51 by 51 by 51-mm cubes were prepared for shrinkage-expansion and compressive-strength tests, respectively. Specimens were demolded after 24 h and placed at 21°C and 100% relative humidity for another 24 h. After that, half the bars were put in lime-saturated water, the other half in air at 50% relative humidity (both cured at 21°C). With respect to the cubes, half were placed in air at 21°C and 50% relative humidity, the others in a moisture chamber. Among the 35 products tested, two cementitious grouts made with special cement and artificial aggregates showed the lowest shrinkage-expansion behavior and the highest compressive strength (over 80 MPa). Two polymer-modified cement-based mortars containing SBR had shown large water expansion and air shrinkage, whereas another cement-based mortar containing SBR showed little shrinkage expansion and high compressive strength. Four of the 12 high sand: epoxy ratio mixes exhibited very large water expansion, whereas most products showed little air shrinkage.
Rapid Chloride Permeability Testing of Silica-Fume Concrete
Authors: Ozyildirim C 
Published: January 2010

Abstract
For long-lasting, reinforced-concrete structures exposed to the environment, low permeability concretes are required. ASTM C 1202 (Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration) is a rapid test that indirectly measures the permeability of concrete. The results of the rapid test have been related to direct measurements of permeability (e.g., ponding test) and have been found to be useful and valid provided that possible interferences are accounted for. For comparisons between tests, similar concretes should be tested at similar ages.
The addition of silica fume results in a reduction in the permeability of concretes. The rapid test has been able to provide information on relative permeability of concretes with or without silica fume. This finding has been confirmed by the results of the extended ponding test.
Limits of Application of the ASTM C 2274 Mortar Bar Test. Comparison with Two Other Standards on Alkali Aggregate Reactivity
Authors: Ranc R , Isabelle H , Yves Clément J , Sorrentino D 
Published: January 2010

Abstract
Mortar bar expansion tests sometimes provide unreliable data concerning the potential reactivity of aggregates in an alkaline medium. The most widely used mortar bar test, known as the Test Method for Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar Bar Method) (ASTM C 227) is a case in point. The alkali-carbonate reaction, which is outside the scope of this standard, will not be discussed in this paper. The procedure related to the storage conditions and the leaching of the alkalies from the bars have been the subject of several recent papers. The investigation presented in this paper covers six deleteriously expansive coarse aggregates, which were correctly evaluated when tested in concrete prisms, but not in mortar bars. The Test Method for Potential Reactivity of Aggregates (Chemical Method) (ASTM C 289) has also been used but was not found to be reliable. Based on data developed from the above tests and a complete petrographic examination, it is concluded that reducing the particle size of the materials as required in the mortar bar test contributes to a decrease in expansion.
A New Nondestructive Testing (NDT): Torsion Test to Evaluate Compressive Strength in Concrete Structures
Authors: Di Maio AA , Traversa LP 
Published: January 2010

Abstract
A new nondestructive test (NDT) for the in-situ compressive strength evaluation of concrete has been developed. Using a torque meter, the failure torsional moment is determined on a small cylinder formed in the structure. Test background, methodology, and results obtained in mortar and concrete are discussed. The effects of w-c ratio, particle shape, maximum size, and types of the coarse aggregates, test age, and curing conditions on the correlation relationship are also reported.
Test results (up to 90 days) showed that correlation curves between compressive strength (fc) and ultimate torsional moment (Mt) depend mainly on the size, shape, and surface texture of the coarse aggregate.
Use of Control Specimens in Freezing and Thawing Testing of Concrete
Authors: Rutherford JH , Langan BW , Ward MA 
Published: January 2010

Abstract
The ability to assess with confidence the potential freezing and thawing durability of concrete is important for long-term evaluations of mix designs and of in-situ concrete.
Test Method for Resistance of Concrete to Rapid Freezing and Thawing (ASTM C 666). Procedure A, which is the subject of this investigation, was designed to provide an indication of the potential freezing and thawing durability of concrete in a freezing and thawing environment. It provides a relative assessment of the frost resistance of the concrete after a given number of freeze-thaw cycles, compared to the initial condition of the specimens.
The principal objective of this investigation was to examine the use of control specimens to improve the interpretation of test data. At each test age, the control specimens are tested and these values used in the calculation of the relative dynamic modulus and weight change.
The control specimens allow the effects of the deterioration process to be separated from the changes in the internal structure due to the hydration process as measured by the transverse frequency. They provide a continuous reference for the test specimens, giving a before and after picture for visual assessment such as scaling.
Toughness Behavior of Fiber-Reinforced Rapid-Set Materials: A Preliminary Study
Authors: Ezeldin AS , Balaguru PN 
Published: January 2010

Abstract
This paper presents the experimental results of a preliminary investigation on fiber-reinforced rapid-set materials. The experimental study was carried out using two commercially available rapid-set materials mixed with steel fibers. The investigation was focused on the flexural strength (modulus of rupture) and toughness of the two composites. Three fiber lengths of 30, 50, and 60 mm were incorporated in this study. Their aspect ratios were: 100 (l = 50 mm, φ = 0.5 mm), 75 (l = 60 mm, φ = 0.8 mm), and 60 (l = 30 mm, φ = 0.5 mm). Three fiber contents, namely 50, 100, and 150 lb/yd3 (30, 60, and 90 kg/m3), were used.
The experimental findings indicate that the addition of steel fibers to rapid-set materials results in an increase in flexural strength and a considerable improvement in flexure toughness.
Properties of High-Strength Concrete Containing Light-, Normal-, and Heavyweight Aggregate
Authors: Nilsen AU , Aïtcin P-C 
Published: January 2010

Abstract
Results of an experimental study on the influence of density of aggregate on mechanical properties of high-strength concrete are presented. Using the same mixture proportions by volume, concretes with very dissimilar mechanical properties were obtained. A comparison of measured static modulus of elasticity to the calculated value obtained by using the equations from various building codes shows that the latter overestimate the modulus significantly. The influence of curing time on the drying shrinkage of concrete was also studied. The results confirm that the coarse aggregate type significantly influences the magnitude of shrinkage.
Development of a New Method for the Determination of Iron Content of Hydraulic Cementitious Materials and Pozzolans
Authors: Richter RE , Poole TS 
Published: January 2010

Abstract
Problems were encountered in the use of the reference method as given in ASTM Test Methods for Chemical Analysis of Hydraulic Cement C 114 for chemical determination of iron in certain cementitious materials including pozzolans, slags, and blended cements. Investigational work was done to overcome these problems. Revised procedures were developed. The revised procedures have been accepted for inclusion in ASTM C 114-88. This report documents the work that led to their development.
Sludge Ash Pellets as Coarse Aggregates in Concrete
Authors: Bhatty JI , Malisci A , Iwasaki I , Reid KJ 
Published: January 2010

Abstract
This work examines the potential of using sintered sludge ash pellets as a substitute for regular coarse aggregate in concrete. The mixing of concrete samples was done by replacing the coarse aggregate with sludge ash pellets in varying proportions following mixing procedures of ASTM Test Method of Making and Curing Concrete Test Specimens in the Laboratory (C 192-88). Specimens were prepared as 50 by 100-mm cylinders and tested for compressive strength for up to 28 days. The results indicate that the incorporation of pellets produced reasonably strong concrete—4900 to 5910 psi (33 to 42 MPa) after 28 days. No adverse effects on concrete strength were observed. Instead, the pellets, being round in shape, enhanced the workability of concrete and resulted in more compact concrete specimens. The net result of substituting the pellets for coarse aggregates is to yield a concrete of lower density since the pellets are formed from a material of lower specific gravity than conventional aggregates. The data show that concrete containing pellets is lighter than regular concrete and has a better strength-to-weight ratio. The peak benefits are a strength-to-weight ratio improvement of more than 15% over regular concrete observed in the specimen with 35% substitution of coarse aggregate by pellets.
Are Small Aggregates Really Better for Making High-Strength Concrete?
Authors: de Larrard F , Belloc A 
Published: January 2010

AbstractIt has been stated recently that 10 to 12 mm is the maximum size of aggregates preferable for making high-strength concrete. A discussion of this statement is presented herein, supported by experimental data on eight concretes (normal-strength and high-strength mixes). It is concluded that, in the range of mixes that can be made with the used components—crushed limestone aggregates, Portland cement, silica fume, and superplasticizer, the classical theory still seems to apply: 20 to 25-mm maximum size aggregates lead to better performances and economy than smaller size aggregates.
Static Modulus of Elasticity of High-Strength Concrete from Pulse Velocity Tests
Authors: Nilsen AU , Aitcin P-C 
Published: January 2010

Abstract
During the past few years there has been a growing interest in predicting and controlling the compressive strength and the elastic properties of concrete. In the case of high-strength concrete, the measurement of the static modulus of elasticity requires special specimen preparation and is fairly time consuming. Since the measurement of the pulse velocity is very easy and a correlation exists between static modulus of elasticity and the stiffness constant from the pulse velocity test, it is proposed to use the latter for predicting the static modulus of elasticity of high-strength concretes with very different elastic properties. The stiffness development can easily be monitored in a fast and inexpensive way, but it is not recommended to use the pulse velocity test to predict the concrete strength. The expression Ed = 1.5 Ec - 5.9 GPa provides a good correlation between the dynamic elastic modulus, Ed, and its static counterpart, Ec.
Assessing Molding Procedure of Compressive Strength Test Specimens for Self-Consolidating Concrete
Authors: Kairouz Abdul Kader , Joudeh Saeed 
Published: January 2010

Abstract
Experimental studies were made by molding the self-consolidating concrete (SCC) with a single layer and comparing strength results with the normal molding procedure. The experiments were conducted to estimate the variation in strength and to provide technique in molding the SCC. The concept was first developed to avoid over-consolidation of concrete and try to simulate the usage of SCC under site conditions. The compressive strength of concrete showed approximately the same results as compared with the compressive strength of concrete that was molded in accordance with the ASTM C31/C31M-06 test method. The degree of concrete control based on standard deviations and coefficient of variations was improved.
Realising social justice in the water sector: 2
Authors: Abbott M. B. , Vojinovic Z. 
Published: January 2010

The second part of this paper is given over to the role of the hydroinformatician in creating sociotechnical environments in which the transmutations necessary to provide states of social justice can be catalysed through the creation of appropriate web-based environments. Some recent exemplifications of these processes within the second paradigm case that is used here are provided in conclusion. In particular, the ways in which the objects presented by the user interfaces to the different classes of stakeholders become transmuted into symbols in the minds of these stakeholders through the active exercise of their imaginations are exemplified and further analysed.
This work has proceeded concurrently with the design, writing and development of the software necessary to realise its aims and ambitions, with special attention being given to the new kinds of user interfaces and viewing facilities that are then required. This work will be described separately by other authors involved in this initiative.
It is emphasised at various junctures that enterprises of this kind carry substantial risks and must be approached with much care and understanding; and indeed the primary reason for writing this paper is to communicate not only the risks, but also the corresponding level of understanding that is necessary to overcome these risks.
Causes of Caregiver Turnover and the Potential Effectiveness of Wage Subsidies for Solving the Long-Term Care Workforce 'Crisis'
Authors: Powers Elizabeth T , Powers Nicholas J 
Published: January 2010

Abstract
Detailed data on private providers of long-term community-based residential services for persons with developmental disabilities permit investigation of the causes of frontline worker turnover. The endogeneity of turnover with compensation variables is accounted for in the estimation using instrumental variables. Turnover is determined by resident characteristics, frontline-worker compensation, and establishment characteristics. The share of higher-need residents and agency size predict higher turnover, while compensation and non-profit status are associated with lower turnover. Our findings indicate that public policies to reduce turnover through compensation subsidization can be effective. Our preferred estimates suggest an approximate one-quarter increase in total compensation would cut turnover by one-third.
The T-Allele of TCF7L2 rs7903146 Associates With a Reduced Compensation of Insulin Secretion for Insulin Resistance Induced by 9 Days of Bed Rest
Authors: Alibegovic Amra C. , Sonne Mette P. , Højbjerre Lise , Hansen Torben , Pedersen Oluf , van Hall Gerrit , Holst Jens J. , Stallknecht Bente , Dela Flemming , Vaag Allan 
Published: January 2010

OBJECTIVE
The aim of this study was to determine whether the type 2 diabetes–associated T-allele of transcription factor 7-like 2 (TCF7L2) rs7903146 associates with impaired insulin secretion to compensate for insulin resistance induced by bed rest.

RESEARCH DESIGN AND METHODS
A total of 38 healthy young Caucasian men were studied before and after bed rest using the hyperinsulinemic-euglycemic clamp technique combined with indirect calorimetry preceded by an intravenous glucose tolerance test. The TCF7L2 rs7903146 was genotyped using allelic discrimination performed with an ABI 7900 system. The genetic analyses were done assuming a dominant model of inheritance.

RESULTS
The first-phase insulin response (FPIR) was significantly lower in carriers of the T-allele compared with carriers of the CC genotype before bed rest, with and without correction for insulin resistance. The incremental rise of FPIR in response to insulin resistance induced by bed rest was lower in carriers of the T-allele (P &lt; 0.001). Fasting plasma glucagon levels were significantly lower in carriers of the T-allele before and after bed rest. While carriers of the CC genotype developed increased hepatic insulin resistance, the TCF7L2 rs7903146 did not influence peripheral insulin action or the rate of lipolysis before or after bed rest.

CONCLUSIONS
Healthy carriers of the T-allele of TCF7L2 rs7903146 exhibit a diminished increase of insulin secretion in response to intravenous glucose to compensate for insulin resistance as induced by bed rest. Reduced paracrine glucagon stimulation may contribute to the impairment of β-cell function in the carriers TCF7L2 rs7903146 T-allele associated with increased risk of type 2 diabetes.
Impact of rs361072 in the Phosphoinositide 3-Kinase p110β Gene on Whole-Body Glucose Metabolism and Subunit Protein Expression in Skeletal Muscle
Authors: Ribel-Madsen Rasmus , Poulsen Pernille , Holmkvist Johan , Mortensen Brynjulf , Grarup Niels , Friedrichsen Martin , Jørgensen Torben , Lauritzen Torsten , Wojtaszewski Jørgen F.P. , Pedersen Oluf , Hansen Torben , Vaag Allan 
Published: January 2010

OBJECTIVE
Phosphoinositide 3-kinase (PI3K) is a major effector in insulin signaling. rs361072, located in the promoter of the gene (PIK3CB) for the p110β subunit, has previously been found to be associated with homeostasis model assessment for insulin resistance (HOMA-IR) in obese subjects. The aim was to investigate the influence of rs361072 on in vivo glucose metabolism, skeletal muscle PI3K subunit protein levels, and type 2 diabetes.

RESEARCH DESIGN AND METHODS
The functional role of rs361072 was studied in 196 Danish healthy adult twins. Peripheral and hepatic insulin sensitivity was assessed by a euglycemic-hyperinsulinemic clamp. Basal and insulin-stimulated biopsies were taken from the vastus lateralis muscle, and tissue p110β and p85α proteins were measured by Western blotting. The genetic association with type 2 diabetes and quantitative metabolic traits was investigated in 9,316 Danes with glucose tolerance ranging from normal to overt type 2 diabetes.

RESULTS
While hepatic insulin resistance was similar in the fasting state, carriers of the minor G allele had lower hepatic glucose output (per-allele effect: −16%, Padd = 0.004) during high physiological insulin infusion. rs361072 did not associate with insulin-stimulated peripheral glucose disposal despite a decreased muscle p85α:p110β protein ratio (Padd = 0.03) in G allele carriers. No association with HOMA-IR or type 2 diabetes (odds ratio 1.07, P = 0.5) was identified, and obesity did not interact with rs361072 on these traits.

CONCLUSIONS
Our study suggests that the minor G allele of PIK3CB rs361072 associates with decreased muscle p85α:p110β ratio and lower hepatic glucose production at high plasma insulin levels. However, no impact on type 2 diabetes prevalence was found.
Landau quantization for an induced electric dipole in the presence of topological defects
Authors: Bakke Knut , Ribeiro Lincoln , Furtado Claudio 
Published: January 2010

AbstractIn this contribution we investigate the non-relativistic quantum dynamics of induced electric dipoles in the presence of a topological defect. We propose an analog of Landau quantization for neutral atoms, where a electric dipole is induced by the electromagnetic field configuration. We investigate this system in the presence of a topological defect and show that it breaks the infinite degeneracy of Landau levels.
Characterization of proteins associating with 5’ terminus of PGHS-1 mRNA
Authors: Bunimov Natalia , Laneuville Odette 
Published: January 2010

AbstractInduction of Prostaglandin Endoperoxide H Synthase-1 (PGHS-1) gene has been previously documented in a few studies during events such as development and cellular differentiation. However, molecular mechanisms governing the regulation of PGHS-1 gene expression and contributing to changes in protein levels are poorly understood. Using the MEG-01 cell model of PGHS-1 gene induction, our laboratory has previously demonstrated that the 5’UTR and the first two exons of PGHS-1 mRNA had a significant impact on decreasing the translational efficiency of a reporter gene and suggested that the presence of a secondary structure is required for conservation of this activity. This 5’end of PGHS-1 mRNA sequence has also been shown to associate with nucleolin protein. In the current study, we set to investigate the protein composition of the mRNP (messenger ribonucleoprotein) associating with the 5’end of PGHS-1 mRNA and to identify its protein members. RNA/protein binding assays coupled with LC-MS analysis identified serpin B1 and NF45 (nuclear factor 45) proteins as potential members of PGHS-1 mRNP complex. Immunoprecipitation experiments using MEG-01 protein extracts validated mass spectrometry data and confirmed binding of nucleolin, serpin B1, NF45 and NF90. The RNA fraction was extracted from immunoprecipitated mRNP complexes and association of RNA binding proteins, serpin B1, NF45 and NF90, to PGHS-1 mRNA target sequence was confirmed by RT-PCR. Together these data suggest that serpin B1, NF45 and NF90 associate with PGHS-1 mRNA and can potentially participate in the formation a single or a number of PGHS-1 ribonucleoprotein complexes, through nucleolin that possibly serves as a docking base for other protein complex members.