bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Edge Restraint on Clip Fastener Loads of Standing Seam Metal Roof Panels
Authors: Dixon Craig R. , Prevatt David O. , Datin Peter L. 
Published: July 2011

Abstract
This study investigates the effect of boundary conditions on the structural load paths within standing seam metal roof (SSMR) panel specimens subjected to uplift wind pressures. The objective is to determine the effect of boundary conditions (restrained or free) on observed load distributions among clip fasteners installed within a SSMR test specimen. Two roof specimens with instrumented clip fasteners were installed in a steel pressure chamber and subjected to static uplift pressures, while measuring panel deflection and clip fastener load distributions. The test specimen boundary conditions were modified in turn to represent field panel location (all free boundaries), gable panel (one restrained boundary, long dimension), eave panel (one restrained boundary, short dimension), and a corner panel (having two adjacent restrained boundaries). The load-displacement characteristics of the SSMR system were determined in a third specimen. The study found statistically significant differences in clip fastener loads, among the first three fastener rows away from the crosswise panel restraint, i.e., eave boundary condition. The gable boundary appeared to have less influence on load on the nearest fasteners. For the eave boundary condition, the measured load on the three exterior fasteners was about 40 % lower than the total fastener load on interior clips located just 3 m (10 ft) away. The results suggest why clip failures seldom occur in corner locations during uplift pressure tests. An empirical design method is proposed for predicting loads on clip fasteners installed near roof boundaries. More importantly, the design of SSMR roofing can be made more efficient, since it is shown that eave clip fasteners carry less than half the load of the interior fasteners, if other failure mechanisms (i.e., sheet tearing or boundary anchor failure) do not control the roof edge failures of installed SSMR.
A New Environmentally Friendly Solvent of Low Toxicity for Crop Protection Formulations
Authors: Vidal Thierry , Bramati Valerio , Murthy Krishnamurthy , Abribat Benoit 
Published: July 2011

Abstract
A new solvent for the crop protection formulations is described. Solvents are essential components in various pesticide formulations. Many traditional solvents used in agricultural applications are currently under scrutiny because of increasing environmental and regulatory concerns. Agrochemical formulators are facing a need to find alternative solvents that are environmentally friendly while continuing to deliver traditional solvent performance. A new polar solvent, an archetype of a novel class of products containing a tertiary amide group combined with an ester function namely Methyl 5-(dimethylamino) 2-methyl 5-oxopentanoate (RHODIASOLV Polarclean) (RHODIASOLV is the registered trade mark of Rhodia, Cranbury, NJ) is described. This new solvent exhibits an outstanding safety and non toxic environmental profile. Additionally, many agrochemical active ingredients have good solubilities in this new solvent. Hansen solubility parameters demonstrate the high level of solvency properties of this ester-amide when compared to the commonly used agrochemical solvents. In addition to meeting the customer requirements on delivering good solvent performance, the raw material utilized in the manufacture of this solvent is a by-product of polyamide manufacture and has been selected to meet the sustainability criteria.
Creep-Fatigue at High Temperature of Notched Single Crystal Superalloys
Authors: Filippini Mauro 
Published: July 2011

Abstract
The effect of hold time on the high temperature notched fatigue strength of the CMSX-4 single crystal superalloy has been experimentally investigated. Notched specimens with orientation 〈001〉 have been tested at 950°C in load control in the low-cycle fatigue (LCF) life regime both without and with dwell. For the same applied stress range (net-section stress), the effect of hold time results in an appreciable reduction of fatigue life. Several scanning electron microscope (SEM) observations of the failed specimens have been made in order to associate the actual failure (crack initiation) location to the correct crystallographic orientation and to the critical location in the notch as given by suitable multiaxial fatigue parameters. Moreover, SEM observations reveal the change of the failure mode from pure fatigue to fatigue/creep conditions. In order to model the material behavior in the notch, stress-strain analysis of the notched specimens was performed by an elastic-plastic finite-element method (FEM) procedure; the parameters describing the material behavior of the single crystal superalloy have been identified by comparison with experimentally determined stress-strain fatigue behavior and creep data of smooth specimens. A suitable model for the assessment of the reduction of fatigue life in creep-fatigue conditions is proposed.
Service Life Assessment of a Low-Slope 55 % Al–Zn Alloy-Coated Steel Standing Seam Roof System
Authors: Haddock Rob , Dutton Ron 
Published: July 2011

Abstract
Published surveys concerning roof service life incorporate estimates from roofing professionals based on their observations and opinions. In cases where roofing products have been in service long enough for the end of life to be observed, these data have some merit, but when end-of-life empirical data are not available, accurate projections are difficult to verify. Other attempts at defining the service life relate to product warranties or lab testing. In the case of standing seam metal roofing, the variability of the materials and installation methods strongly colors the survey opinions. In steel roofing, this variability includes that of the steel thickness, the metallic coating type and thickness, the presence or absence of paint films, the types of sealants, the seam-folding details, and other construction or installation details. Related accessories and flashings of different materials and designs further confuse survey criteria and results. In the case of 55 % Al–Zn alloy-coated steel roofing systems, the prediction of service life is complicated by the fact that the product has been commercially available for under 40 years, and end of life has rarely been observed. In this paper, we combine field inspection procedures with a novel technique for securing roof samples for subsequent laboratory analysis in order to enable the prediction of roof service life for a 55 % Al–Zn alloy-coated steel roof in Denver, CO. The performance of other roof components is also quantified. A methodology is then presented that utilizes the current best practices, together with the results of this roof analysis, to predict the total roof service life of similar constructions when built using today’s practices. This work confirms previously published work that used experimental corrosion specimens to establish the long-term durability of 55 % Al–Zn alloy-coated steel. It is suggested that this work can be replicated in order to develop meaningful corrosion and material performance data for any climate in which this type of roof is constructed.
Creep and Environmental Effects on the High Temperature Creep-Fatigue Behavior of Alloy 617
Authors: Carroll L. J. , Cabet C. , Madland R. , Wright R. N. 
Published: July 2011

Abstract
Alloy 617 is the leading candidate material for an intermediate heat exchanger (IHX) of the very high temperature reactor (VHTR), expected to have an outlet temperature as high as 950°C. Acceptance of Alloy 617 in Section III of the ASME Code for nuclear construction requires a detailed understanding of the creep-fatigue behavior. Strain-controlled low cycle fatigue (LCF) tests including hold times up to 1800 s at maximum tensile strain were conducted at 950°C and a total strain range of 0.3 % in air and in a simulated VHTR impure helium. For similar test conditions, the creep-fatigue behavior was globally similar in both environments. The fatigue resistance decreased when a hold time was added at peak tensile strain, consistent with the observed change in fracture mode from transgranular to intergranular. Further increases in the tensile hold time, beyond 180 s, were not detrimental to the creep-fatigue resistance. The influence of oxidation on the fatigue crack initiation and propagation is discussed. Bulk damage in the form of grain boundary cracking was present in the interior of the creep-fatigue specimens. This bulk cracking was quantified and found to be similar for hold times of up to 1800 s consistent with the saturation in failure lives.
Advanced Ductility Exhaustion Methods for the Calculation of Creep Damage During Creep-Fatigue Cycling
Authors: Spindler Mike W , Payten Warwick M 
Published: July 2011

Abstract
The thermal mechanical cycling of high temperature components can result in creep-fatigue cycles in which the creep dwell has a wide variety of positions within the cycle. During in-phase cycling the creep dwell is placed at the maximum strain in the cycle. Out of phase cycling gives compressive dwells and phase cycling between 0° and 180° gives a cycle in which the dwell is placed before the maximum strain is reached, i.e., at an intermediate position within the cycle. Furthermore, components often experience cycles with a variety of different strain amplitudes, which can result in cycle sequencing effects. The effects of these different types of creep dwells have been investigated as part of the development programme for the R5 High Temperature Life Assessment Procedure. The materials included in the R5 programme were two low alloy ferritic steels; a cast 1CrMoV and a cast 1/2 CrMoV and three austenitic stainless steels; a type 316H steel, a cast type 304L, and a type 347 weld metal. The analysis of these tests has resulted in the proposal of a new method to calculate creep damage. This has been shown to give better predictions for the creep damage at failure in laboratory tests compared with both the current R5 ductility exhaustion approach and the time fraction approach, which is used in typical design codes such as ASME III and RCC-MR. In particular, the new method gives significantly improved predictions of creep damage at failure for creep-fatigue cycles with intermediate dwells and for cycles with low strain ranges, which are of particular relevance to the service cycles in real plant. This paper reviews the findings of the work on the new method, the effects of multiaxial states of stress and the effects of compressive dwells.
Fetal and infant growth and the risk of obesity during early childhood: the Generation R Study
Authors: Mook-Kanamori Dennis O , Durmuş Büşra , Sovio Ulla , Hofman Albert , Raat Hein , Steegers Eric A P , Jarvelin Marjo-Riitta , Jaddoe Vincent W V 
Published: July 2011

ObjectiveTo examine whether infant growth rates are influenced by fetal growth characteristics and are associated with the risks of overweight and obesity in early childhood.DesignThis study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life onward.MethodsFetal growth characteristics (femur length (FL) and estimated fetal weight (EFW)) were assessed in the second and third trimesters and at birth (length and weight). Infant peak weight velocity (PWV), peak height velocity (PHV), and body mass index at adiposity peak (BMIAP) were derived for 6267 infants with multiple height and weight measurements.ResultsEFW measured during the second trimester was positively associated with PWV and BMIAP during infancy. Subjects with a smaller weight gain between the third trimester and birth had a higher PWV. FL measured during the second trimester was positively associated with PHV. Gradual length gain between the second and third trimesters and between the third trimester and birth were associated with higher PHV. Compared with infants in the lowest quintile, the infants in the highest quintile of PWV had strongly increased risks of overweight/obesity at the age of 4 years (odds ratio (95% confidence interval): 15.01 (9.63, 23.38)).ConclusionFetal growth characteristics strongly influence infant growth rates. A higher PWV, which generally occurs in the first month after birth, was associated with an increased risk of overweight and obesity at 4 years of age. Longer follow-up studies are necessary to determine how fetal and infant growth patterns affect the risk of disease in later life.
Decreased expression of genes involved in oxidative phosphorylation in human pancreatic islets from patients with type 2 diabetes
Authors: Olsson Anders H , Yang Beatrice T , Hall Elin , Taneera Jalal , Salehi Albert , Dekker Nitert Marloes , Ling Charlotte 
Published: July 2011

ObjectiveGene expression alterations, especially in target tissues of insulin, have been associated with type 2 diabetes (T2D). In this study, we examined if genes involved in oxidative phosphorylation (OXPHOS) show differential gene expression and DNA methylation in pancreatic islets from patients with T2D compared with non-diabetic donors.Design and methodsGene expression was analyzed in human pancreatic islets from 55 non-diabetic donors and nine T2D donors using microarray.ResultsWhile the expected number of OXPHOS genes with reduced gene expression is 7.21, we identified 21 downregulated OXPHOS genes in pancreatic islets from patients with T2D using microarray analysis. This gives a ratio of observed over expected OXPHOS genes of 26.37 by aχ2-test withP=2.81×10−7. The microarray data was validated by qRT-PCR for four selected OXPHOS genes:NDUFA5, NDUFA10, COX11, andATP6V1H. All four OXPHOS genes were significantly downregulated in islets from patients with T2D compared with non-diabetic donors using qRT-PCR (P≤0.01). Furthermore, HbAlc levels correlated negatively with gene expression ofNDUFA5, COX11, andATP6V1H(P<0.05). Gene expression ofNDUFA5, NDUFA10, COX11, andATP6V1Hcorrelated positively with glucose-stimulated insulin secretion (P<0.03). Finally, DNA methylation was analyzed upstream of the transcription start forNDUFA5, COX11, andATP6V1H. However, none of the analyzed CpG sites in the three genes showed differences in DNA methylation in islets from donors with T2D compared with non-diabetic donors.ConclusionPancreatic islets from patients with T2D show decreased expression of a set of OXPHOS genes, which may lead to impaired insulin secretion.
Coalescence-Time Distributions in a Serial Founder Model of Human Evolutionary History
Authors: DeGiorgio Michael , Degnan James H , Rosenberg Noah A 
Published: July 2011

AbstractSimulation studies have demonstrated that a variety of patterns in worldwide genetic variation are compatible with the trends predicted by a serial founder model, in which populations expand outward from an initial source via a process in which new populations contain only subsets of the genetic diversity present in their parental populations. Here, we provide analytical results for key quantities under the serial founder model, deriving distributions of coalescence times for pairs of lineages sampled either from the same population or from different populations. We use these distributions to obtain expectations for coalescence times and for homozygosity and heterozygosity values. A predicted approximate linear decline in expected heterozygosity with increasing distance from the source population reproduces a pattern that has been observed both in human genetic data and in simulations. Our formulas predict that populations close to the source location have lower between-population gene identity than populations far from the source, also mirroring results obtained from data and simulations. We show that different models that produce similar declining patterns in heterozygosity generate quite distinct patterns in coalescence-time distributions and gene identity measures, thereby providing a basis for distinguishing these models. We interpret the theoretical results in relation to their implications for human population genetics.
A Drosophila Model for Genetic Analysis of Influenza Viral/Host Interactions
Authors: Adamson Amy L , Chohan Kultaran , Swenson Jennifer , LaJeunesse Dennis 
Published: July 2011

Abstract
Influenza viruses impose a constant threat to vertebrates susceptible to this family of viruses. We have developed a new tool to study virus–host interactions that play key roles in viral replication and to help identify novel anti-influenza drug targets. Via the UAS/Gal4 system we ectopically expressed the influenza virus M2 gene in Drosophila melanogaster and generated dose-sensitive phenotypes in the eye and wing. We have confirmed that the M2 proton channel is properly targeted to cell membranes in Drosophila tissues and functions as a proton channel by altering intracellular pH. As part of the efficacy for potential anti-influenza drug screens, we have also demonstrated that the anti-influenza drug amantadine, which targets the M2 proton channel, suppressed the UAS-M2 mutant phenotype when fed to larvae. In a candidate gene screen we identified mutations in components of the vacuolar V1V0 ATPase that modify the UAS-M2 phenotype. Importantly, in this study we demonstrate that Drosophila genetic interactions translate directly to physiological requirements of the influenza A virus for these components in mammalian cells. Overexpressing specific V1 subunits altered the replication capacity of influenza virus in cell culture and suggests that drugs targeting the enzyme complex via these subunits may be useful in anti-influenza drug therapies. Moreover, this study adds credence to the idea of using the M2 “flu fly” to identify new and previously unconsidered cellular genes as potential drug targets and to provide insight into basic mechanisms of influenza virus biology.
Gas-Compositional Effects on Mineralogical Reactions in Carbon Dioxide Sequestration
Authors: Mandalaparty Prashanth , Deo Milind , Moore Joseph 
Published: July 2011

Summary
It may be possible to lower costs of carbon capture and sequestration by keeping constituents such as sulfur dioxide (SO2) in the flue-gas stream. The reactive behavior of pure carbon dioxide (CO2) and CO2+SO2 mixtures within a geologically realistic environment was examined in this paper. The experimental apparatus consisted of a series of high-pressure reactors operated at different conditions and with different feed-gas compositions to observe changes in both the rock and water compositions. The rock consisted of equal proportions of quartz, calcite, andesine, dolomite, chlorite, and magnesite (constituents in arkose or dirty sandstone). The brine was prepared from laboratory-grade sodium chloride. Several long-term batch experiments with pure CO2 were carried out at different temperatures. Each mineral in the mixture showed evidence of participating in the geochemical reactions. Layers of calcite were seen growing on the surface of the arkose. Analcime deposits were omnipresent, occurring either as large connected aggregates or as deposits on the surfaces of other minerals (quartz). Calcite depositions were observed as amorphous masses intergrown with the feed. The CO2+SO2 mixture experiments showed growth of euhedral anhydrite crystals and pronounced dissolution patterns over the examined surfaces. The growth of these new phases would lead to significant changes in the petrophysical properties of the rock. The trends in ionic-concentration changes in the aqueous phase complemented the changes in the rock chemistry.
Probabilistic Modeling for Decision Support in Integrated Operations
Authors: Giese Martin , Bratvold Reidar B. 
Published: July 2011

SummaryWe report work carried out within the project on collaborative decision support for integrated operations (CODIO). As one part of this project, we have designed a system to provide assistance in operational decisions based on real-time sensor readings in a typical scenario: While drilling close to the transition to a high-pressure formation, a gas influx is observed. The drilling team needs to decide whether to circulate, increase the mud weight, plug back, or set a casing.After a brief description of the technology we used to model decision problems [Bayesian networks, influence diagrams (IDs)], we describe our case study and discuss the particular challenge of applying decision analysis to the kind of operational decision that is central to the case study. We then proceed to apply the method of decision analysis to our case study. We discuss how the resulting ID was tested using a simulation and discuss challenges in applying the technology, as well as lessons learned in the process. We also give a list of desiderata to establish better decision-making practices in the petroleum industry.
Propagation and Retention of Viscoelastic Surfactants Following Matrix-Acidizing Treatments in Carbonate Cores
Authors: Yu M.. , Mahmoud M.A.. A. , Nasr-El-Din H.A.. A. 
Published: July 2011

SummaryViscoelastic surfactants have been used extensively in the field. They have the ability to form long rod-like micelles with an increase in pH and calcium concentration, which results in increasing the viscosity and elasticity of partially spent acids. There is ongoing debate in the industry about whether the gel generated by these surfactants causes formation damage, especially in dry-gas wells. The objectives of the present study are to quantitatively determine surfactant retention in calcite cores and assess the benefits of using mutual solvents to break the surfactant gel formed inside the cores.Coreflood tests were performed using Pink Desert limestone cores (1.5 in. in diameter and 20 in. in length). The cores were injected with a surfactant-based acid that contained 15 wt% HCl, 7 vol% viscoelastic surfactant, and 0.3 vol% corrosion inhibitor. Coreflood tests were conducted at a constant injection flow rate ranging from 1.5 to 40 cm3/min. Surfactant and calcium concentrations were measured in the injected acid and core effluent. Mutual solvent (ethylene glycol monobutyl ether) was used in several tests to break surfactant gel.Propagation of viscoelastic surfactants in linear calcite cores was found to be a function of flow rate. Surfactant lagged calcium in the core effluent samples, especially at low flow rates. The volume of acid needed to break through the core and the amount of surfactant retained varied with acid injection rate, and exhibited a minimum at 10 cm3/min. A significant amount of surfactant was retained in the cores. Injection of 2 pore volumes (PV) of 10 vol% mutual solvent removed only 20% of the surfactant injected. Based on these results, there is a need to use internal breakers when surfactant-based acids are used in dry-gas wells or water injectors.