bluuebunny/crossref_metadata_2025 huggingface dataset:
AUTOMATIC PRODUCTION OF TEST DATA WITH A MULTIPLE BATCH-OPTIMISTIC METHOD
Authors: SOFOKLEOUS ANASTASIS A. , ANDREOU ANDREAS S.
Published: March 2009

Recent research on software testing focuses on integrating techniques, such as computational intelligence, with special purpose software tools so as to minimize human effort, reduce costs and automate the testing process. This work proposes a complete software testing framework that utilizes a series of specially designed genetic algorithms to generate automatically test data with reference to the edge/condition testing coverage criterion. The framework utilizes a program analyzer, which examines the program's source code and builds dynamically program models for automatic testing, and a test data generation system that utilizes genetic algorithms to search the input space and determine a near to optimum set of test cases with respect to the testing coverage criterion. The performance of the framework is evaluated on a pool of programs consisting of both standard and random-generated programs. Finally, the proposed test data generation system is compared against other similar approaches and the results are discussed.
SOA-BASED CONTENT DELIVERY MODEL FOR MOBILE INTERNET NAVIGATION
Authors: YANG STEPHEN J. H. , ZHANG JIA , TSAI JEFFREY J. P. , HUANG ANGUS F. M.
Published: March 2009

This paper presents a Service Oriented Architecture (SOA)-based content delivery model to facilitate mobile content delivery. The main contribution of this paper is the design and development of an SOA-equipped content delivery system based on a context-driven, access-controlled, profile-favored, and history-maintained (CAPH) model. We embody the generic model-view-controller (MVC) model to support a dynamic content adaptation technique based on mobile users' contextual environments. Self-adaptable presentation objects and modules are modeled as universal Web services resources, so that their interactions are formalized into Web services operations for high interoperability. Experimental results demonstrate that our proposed SOA-based model makes it easy to configure and construct a flexible Web content delivery system on the mobile Internet.
Implicit Difference Inequalities Corresponding to First‐Order Partial Differential Functional Equations
Authors: Kamont Z. , Kropielnicka K.
Published: March 2009

We give a theorem on implicit difference functional inequalities generated
by mixed problems for nonlinear systems of first‐order partial
differential functional equations. We apply this result in the investigations
of the stability of difference methods. Classical solutions of mixed
problems are approximated in the paper by solutions of suitable implicit
difference schemes. The proof of the convergence of difference method
is based on comparison technique, and the result on difference functional
inequalities is used. Numerical examples are presented.
A long-lasting, plasmin-activatable thrombin inhibitor aids clot lysis in vitro and does not promote bleeding in vivo
Authors: Eltringham-Smith Louise , Gataiance Sharon , Bhakta Varsha , Sheffield William
Published: March 2009

The leech protein hirudin is a potent inhibitor of thrombin, but clinical use of recombinant hirudin is restricted by haemorrhagic risks, and complicated by hirudin’s rapid clearance from the circulation. We previously employed albumin fusion to slow hirudin variant 3 (HV3) clearance. In this study, we hypothesized that reconfiguration of the chimera, appending human serum albumin (HSA) to the N-terminus of HV3, with an intervening plasmin cleavage site, would create a slowly cleared, plasmin-activatable HV3. Potential plasmin cleavage sites were screened by expression in Escherichia coli, interposed between glutathione sulfotransferase and HV3 domains. The most reactive sequence (GSGIYR-ITY) was recreated in C-terminally His-tagged albumin fusion protein HSACHV3, expressed in Pichia pastoris yeast and purified by nickel-chelate affinity chromatography. HSACHV3 showed no thrombin inhibitory activity in the absence of plasmin, but liberated active HV3 in a time- and concentration-dependent manner in its presence. In a discontinuous clot assay involving clot-bound thrombin, HSACHV3 assisted clot lysis by limiting clot extension in a tPA- and concentration-dependent manner. Similar results were obtained in plasma at higher concentrations of HSACHV3. The chimeric protein exhibited much slower clearance in mice than unfused HV3, and indistinguishable pharmacokinetics from unfused recombinant HSA. In a mouse tail transection bleeding model, doses of HSACHV3 identical to those of HV3 that elicited a four-fold increase in the volume of shed blood were without effect. Our results suggest that HSACHV3 is a fully latent, plasmin activatable, long-lasting hirudin, of potential benefit in thrombotic disorders resistant to natural or pharmacological clot lysis.
Sphingosine-1-phosphate: A bioactive lipid that confers high-density lipoprotein with vasculoprotection mediated by nitric oxide and prostacyclin
Authors: Badimon Lina , Rodríguez Cristina , González-Díez María , Martínez-González José
Published: March 2009

Sphingosine-1-phosphate (S1P) is a bioactive lipid generated in the intracellular membranes from the metabolism of sphingomyelin. Once secreted/exported by cells of haematopoietic origin and vascular cells S1P interacts with plasma proteins and accumulates in high-density lipoprotein (HDL). Growing evidence indicates that HDL-associated S1P is responsible for the beneficial effects of these lipoproteins on vasorelaxation, cell survival, cell adhesiveness, angiogenesis and synthesis of two powerful endogenous anti-atherogenic and anti-thrombotic molecules such as nitric oxide (NO) and prostacyclin (PGI2). It is likely that vascular effects of HDL-S1P are regulated by the local expression of S1P receptors. Five G protein-coupled receptors (S1P1 to S1P5), with differential expression patterns and dissimilar coupling mechanism to G protein subunits, have been identified in the vasculature. This review is focused on the central role of S1P as a bioactive component that confers vasculoprotective properties to HDL by eliciting a wide range of biological responses on endothelial and smooth muscle cells largely dependent on the up-regulation of NO and prostacyclin.
Autoimmune mediated G-protein receptor activation in cardiovascular and renal pathologies
Authors: Philippe Aurélie , Catar Rusan , Hegner Björn , Dragun Duska
Published: March 2009

Antibodies directed against G-protein coupled receptors (GPCR) can act as allosteric receptor agonists or antagonists. Prototypic disease for agonistic antibody action is a Graves disease of the thyroid gland where antibodies that stimulate G-protein coupled thyroid-stimulating hormone receptor (TSHR) were first described 50 years ago. Myasthenia gravis is the prototype for antagonistic autoimmune actions, where antibodies directed against the nicotinic acetylcholine receptor (AChR) cause blockade of neuromuscular junctions. Antibodies and B-cells are increasingly recognised as major modulators of various cardiovascular and renal pathologies. We aim to critically review the notion that antibodies targeting other GPCRs may amplify or cause various cardiovascular and renal pathologies and summarise the current state of research, as well as perspectives in diagnostic and therapeutic strategies. In terms of targets we will focus on the α-adrenergic receptor (α1AR), the β-adrenergic receptor (β1AR), and the angiotensin II type 1 receptor (AT1R).
Do common prothrombotic mutations influence the risk of cerebral ischaemia in patients with patent foramen ovale?
Authors: Grassi Mario , Zotto Elisabetta Del , Giossi Alessia , Volonghi Irene , Costa Paolo , Grau Armin , Magoni Mauro , Padovani Alessandro , Lichy Christoph , Pezzini Alessandro
Published: March 2009

Conflicting results are available on the association of prothrombotic genetic abnormalities with patent foramen ovale (PFO)-related cerebral ischaemia. We comprehensively sought and identified studies of the association of both the factor V Leiden (FVG1691A mutation) and the prothrombin mutation (PTG20210A mutation) with PFO-related cerebral ischaemia and did meta-analyses to assess the evidence for such a relation. We analysed data from six eligible studies in 856 cases and 1,001 control subjects. Additional unpublished data from a new series including 463 subjects were also entered into the analysis. The PTG20210A variant was significantly associated with PFO-related stroke in comparison with both control subjects (odds ratio [OR] 3.85; 95% confidence interval [CI] 2.22 to 6.66) and non-PFO-associ ated stroke patients (OR 2.31; 95% CI 1.20 to 4.43), whereas a trend toward an association was observed for the FVG1691A mutation (OR 1.18; 95% CI 0.73 to 1.90, compared to control subjects; OR 1.14; 95% CI 0.62 to 2.09, compared to non-PFO-associated stroke patients). The status of carrier of either the FVG1691A mutation or the PTG20210A variant was associated with a risk for stroke of 1.98 (95% CI 1.38 to 2.83) and 1.62 (95% CI 1.03 to 2.57), as compared to control subjects and non-PFO-associated stroke patients, respectively. Addition of common prothrombotic genetic variants to standard initial screening may contribute to stratifying PFO-associated stroke patients at different risk of ischaemic events and targeting secondary prevention strategies.
The Effects of Mesoscale Ocean–Atmosphere Coupling on the Large-Scale Ocean Circulation
Authors: Hogg Andrew Mc C. , Dewar William K. , Berloff Pavel , Kravtsov Sergey , Hutchinson David K.
Published: March 2009

Small-scale variation in wind stress due to ocean–atmosphere interaction within the atmospheric boundary layer alters the temporal and spatial scale of Ekman pumping driving the double-gyre circulation of the ocean. A high-resolution quasigeostrophic (QG) ocean model, coupled to a dynamic atmospheric mixed layer, is used to demonstrate that, despite the small spatial scale of the Ekman-pumping anomalies, this phenomenon significantly modifies the large-scale ocean circulation. The primary effect is to decrease the strength of the nonlinear component of the gyre circulation by approximately 30%–40%. This result is due to the highest transient Ekman-pumping anomalies destabilizing the flow in a dynamically sensitive region close to the western boundary current separation. The instability of the jet produces a flux of potential vorticity between the two gyres that acts to weaken both gyres.
The Shape of Things to Come: Why Is Climate Change So Predictable?
Authors: Baker Marcia B. , Roe Gerard H.
Published: March 2009

The framework of feedback analysis is used to explore the controls on the shape of the probability distribution of global mean surface temperature response to climate forcing. It is shown that ocean heat uptake, which delays and damps the temperature rise, can be represented as a transient negative feedback. This transient negative feedback causes the transient climate change to have a narrower probability distribution than that of the equilibrium climate response (the climate sensitivity). In this sense, climate change is much more predictable than climate sensitivity. The width of the distribution grows gradually over time, a consequence of which is that the larger the climate change being contemplated, the greater the uncertainty is about when that change will be realized. Another consequence of this slow growth is that further efforts to constrain climate sensitivity will be of very limited value for climate projections on societally relevant time scales. Finally, it is demonstrated that the effect on climate predictability of reducing uncertainty in the atmospheric feedbacks is greater than the effect of reducing uncertainty in ocean feedbacks by the same proportion. However, at least at the global scale, the total impact of uncertainty in climate feedbacks is dwarfed by the impact of uncertainty in climate forcing, which in turn is contingent on choices made about future anthropogenic emissions.
Response of the West African Monsoon to the Madden–Julian Oscillation
Authors: Lavender Sally L. , Matthews Adrian J.
Published: March 2009

Observations show that rainfall over West Africa is influenced by the Madden–Julian oscillation (MJO). A number of mechanisms have been suggested: 1) forcing by equatorial waves; 2) enhanced monsoon moisture supply; and 3) increased African easterly wave (AEW) activity. However, previous observational studies are not able to unambiguously distinguish between cause and effect. Carefully designed model experiments are used to assess these mechanisms. Intraseasonal convective anomalies over West Africa during the summer monsoon season are simulated in an atmosphere-only global circulation model as a response to imposed sea surface temperature (SST) anomalies associated with the MJO over the equatorial warm pool region. 1) Negative SST anomalies stabilize the atmosphere leading to locally reduced convection. The reduced convection leads to negative midtropospheric latent heating anomalies that force dry equatorial waves. These waves propagate eastward (Kelvin wave) and westward (Rossby wave), reaching Africa approximately 10 days later. The associated negative temperature anomalies act to destabilize the atmosphere, resulting in enhanced monsoon convection over West and central Africa. The Rossby waves are found to be the most important component, with associated westward-propagating convective anomalies over West Africa. The eastward-propagating equatorial Kelvin wave also efficiently triggers convection over the eastern Pacific and Central America, consistent with observations. 2) An increase in boundary layer moisture is found to occur as a result of the forced convective anomalies over West Africa rather than a cause. 3) Increased shear on the African easterly jet, leading to increased AEW activity, is also found to occur as a result of the forced convective anomalies in the model.
Large Eddy Simulations of Upper-Ocean Response to a Midlatitude Storm and Comparison with Observations*
Authors: Li Ming , Vagle Svein , Farmer David M.
Published: March 2009

A large eddy simulation (LES) model is used to investigate an upper-ocean response to a fall storm in the open ocean of the North Pacific Ocean. The storm is characterized by rapid increases in wind speed and surface heat loss but a relatively steady wave field. The LES model shows that surface convergence zones or windrows organize into line patterns aligned with the wind direction, evolving from nearly parallel lines to irregular structures featuring Y junctions as the wind speed increases. The downwelling-to-upwelling velocity ratio ranges between 1.2 and 1.6, indicating a moderate level of asymmetry between the downwelling and upwelling plumes in Langmuir circulation. During the storm, the turbulent Langmuir number Lat increases from 0.2 to 0.5 while the vertical turbulence intensity σw2 decreases from 1.4 to 0.7 u*2, where u* is the friction velocity. The order of turbulence intensities in three directions switches from crosswind ≈ vertical > downwind directions to downwind > crosswind > vertical directions. This suggests a transition from Langmuir to shear turbulence as the storm progresses. The Hoennikker number (Ho) remains below 0.1 and the strong evaporative heat loss does not contribute much to the turbulence generation in the ocean mixed layer. The LES results are compared with in situ and acoustic measurements collected during the storm. Patterns of model-predicted near-surface downwelling zones are in good agreement with horizontal distributions of bubble clouds revealed in sidescan sonar images. Striking similarity is also found in the temperature anomalies between the LES model and high-resolution thermistor chain measurements.
The Effects of Precipitation on Cloud Droplet Measurement Devices
Authors: Baker Brad , Mo Qixu , Lawson R. Paul , O’Connor Darren , Korolev Alexei
Published: March 2009

Aircraft in situ observations of precipitation during the Rain in Cumulus over the Ocean (RICO) field project are used to study and parameterize the effects of precipitation on cloud probes. Specifically, the effects of precipitation on the Forward Scattering Spectrometer Probe, the King cloud liquid water hot-wire probe, and the particle volume monitor are parameterized as linear functions of the precipitation water content.
Modernity and Confucian Political Philosophy in a Globalizing World
Authors: Ming Chen
Published: March 2009

The scholarship of Confucianism in China is in the process of restoration. Its historical missions are two-fold. It should preserve Chinese national characters and promote China's modernization. These objectives are partly in conflict with each other. To realize the former objective, it is necessary to stress a historical continuity and consistency, to re-examine and justify the preservation of classical Confucian ideas and values in order to provide spiritual support for Chinese cultural identity and social cohesion. As to the latter objective, it is necessary to reinterpret some part of the classical ideas and values and link them with the modern values such as liberty, justice and democracy. This essay analyzes the position of three Confucianist scholars, Jiang Qing, Chen Ming and Kang Xiaoguang, to show the different balances between conservatism and reformers when their writings confront the challenges of modernization and globalization.
The Most Fashionable and the Most Relevant: A Review of Contemporary Chinese Political Philosophy
Authors: Lian Zhou
Published: March 2009

This paper presents a review of the main trends of contemporary political philosophy in China. First, it provides a general picture of the presence of contemporary western political philosophy in China. It shows how the different political positions (New Left, liberalist, conservative) relate to the different stances adopted before Western authors, and focuses in particular on the reception of Carl Schmitt and Leo Strauss in China's academic and cultural circles. Second, it provides an account of what might be contemporary Chinese political philosophers’ unique contributions to political theory. It pays particular attention to two Chinese scholars, Gan Yang and Zhao Tingyang. While both of them specialize in western philosophy, they neither echo western political philosophy nor repeat traditional Chinese political thought, but, rather, commit themselves to a transformation of Chinese tradition thought, in order to figure out some original and debatable theories. By focusing on analyzing these philosophers’ ideas and influences, the author hopes to answer two distinct but interrelated questions: how and why are they are so fashionable or popular, and whose thought might retain some pertinence in the context and issues of Chinese political tradition and the existing political practices.
Commotio Cordis
Authors: Palacio Luis E. , Link Mark S.
Published: March 2009

Content:

Commotio cordis is blunt, nonpenetrating trauma to the chest resulting in irregular heart rhythm and often leading to sudden death. This article presents the epidemiology, variables leading to commotio cordis, theories on predisposing factors, diagnosis, treatment, treatment outcomes, and return-to-play recommendations.

Evidence Acquisition:

A PubMed (MEDLINE) search for commotio cordis was conducted on July 1, 2008, and it yielded 106 results, of which 26 were used for this review, including experimental models, simulation studies, case analysis studies, case reports, general recommendation, review articles, and editorials.

Results:

There are more than 190 reported cases of commotio cordis in the United States. Forty-seven percent of reported cases occurred during athletic participation. Commotio cordis is the second-most common cause of sudden cardiac death in athletes. Occurrence of commotio cordis is related to time of impact during the cardiac cycle, direct impact over the heart, the hardness and speed of the projectile, and the ineffectiveness of chest barriers. As a result, the US Consumer Product Safety Commission recommends that softer “safety” baseballs be used for youth baseball. Resuscitation using defibrillation was effective in only 15% of cases. Resuscitation within 3 minutes resulted in a survival rate of 25% (17 of 68 cases). Survival drops to 3% when resuscitation is delayed beyond 3 minutes. Survival of commotio cordis has risen from 10% to 15% since 2001. Reduced ventricular ejection fraction has been identified in some commotio cordis survivors.

Conclusion:

Preventive measures, such as using soft “safety” balls and making automated external defibrillators available at sporting venues, can reduce commotio cordis morbidity and mortality. Chest protector designs can be improved to enhance protection. Return to play is best left to clinical judgment given that data are lacking with regard to susceptibility for reoccurrence.
EBSD study of solidification characteristics of austenitic stainless steel weld pool
Authors: Huang Y. M. , Wu Y. M. , Pan C. X.
Published: March 2009

This present paper studied the solidification characteristics of a high Fe–Cr–Ni austenitic stainless steel weld pool using an EBSD system. The results revealed that the crystallography of the weld metal grains was affected by both the heat affected zone (HAZ) base metal grains at the fusion boundary and the thermal condition in weld pool. It exhibited an orientation relationship of <100> // <100> and {100} // {100} between the HAZ base metal and weld metal along the fusion boundary, which was resulted from the epitaxial growth in the weld pool. Additionally, a high fibre texture <100> toward the weld centreline was determined by the effect of the competitive mechanism at the beginning of the weld solidification.
Isothermal embrittlement of Fe–8Mn alloys at 450°C
Authors: Nikbakht F. , Nasim M. , Davies C. , Wilson E. A. , Adrian H.
Published: March 2009

Two Fe–8Mn alloys, one of which is alloy 193, stabilised with 0·17%Ti and 0·18%Al, were austenitised at 900°C, ice brine quenched and their DBTTs determined. In this condition, brittle fractures were predominantly cleavage, and thermodynamic calculations on alloy 193 showed that there were 0·0025 wt-%C and <0·03 ppm N in solid solution. Alloys were tempered for 6 min, 1 h and 10 h at 450°C and their DBTTs again determined; in this case, brittle fractures were mainly intergranular. In alloy 193, DBTT rose from 27 to 125°C in 6 min. Hardness values at 450°C were also monitored and the variation of hardness with time is discussed. It is thought that brittle fracture in alloy 193 is due to segregation of Mn per se to prior austenite grain boundaries, unlike an earlier investigation of a pure Fe–8Mn alloy (K1525), where embrittlement was due to a Mn–N and to a lesser extent a Mn–P interaction at prior austenite grain boundaries. The driving force for Mn segregation to prior austenite grain boundaries is thought to be the initial formation of reverted austenite at such sites.
Endogenous IL-17 contributes to reduced tumor growth and metastasis
Authors: Kryczek Ilona , Wei Shuang , Szeliga Wojciech , Vatan Linhua , Zou Weiping
Published: March 2009

It has been reported that ectopically expressed interleukin-17 (IL-17) in tumor cells suppresses tumor progression through enhanced antitumor immunity in immune competent mice or promote tumor progression through an increase in inflammatory angiogenesis in immune-deficient mice. The role of endogenous IL-17 in tumor immunity remains undefined. Here we showed that tumor growth and lung metastasis were enhanced in IL-17–deficient mice, associated with decreased interferon-γ+ natural killer cells and tumor specific interferon-γ+ T cells in the tumor draining lymph nodes and tumors. Together with the published data showing that in vitro transforming growth factor-β and IL-6–polarized Th17 cells induce tumor regression, our work supports the notion that endogenous IL-17 or/and Th17 cells may play a protective role in tumor immunity.
Direct Observation of Well-dispersed Pt Nanoparticles inside the Pores of Mesoporous Carbon through the Cross Section of Pt/Mesoporous Carbon Particles
Authors: Hayashi Akari , Kimijima Ken’ichi , Miyamoto Junichi , Yagi Ichizo
Published: March 2009

Pt nanoparticles were deposited on mesoporous carbon support using two different Pt precursors, and the difference in mass activity toward oxygen reduction between the two was successfully examined through direct observation of Pt nanoparticles inside the mesopores. Existence of 1-nm-sized Pt particles on the wall of mesopores was observed, and catalytic activity was higher if the size of Pt particles inside the pores was smaller. The size and stability of Pt catalysts encapsulated in nanospace is key for catalytic activity.
Peritumoral Activated Hepatic Stellate Cells Predict Poor Clinical Outcome in Hepatocellular Carcinoma After Curative Resection
Authors: Ju Min-Jie , Qiu Shuang-Jian , Fan Jia , Xiao Yong-Sheng , Gao Qiang , Zhou Jian , Li Yi-Wei , Tang Zhao-You
Published: March 2009

The inflammatory components of the liver remnant after hepatocellular carcinoma (HCC) resection are of prognostic importance. We evaluated prognostic potential of peritumoral activated hepatic stellate cells (HSCs) in 130 HCC cases. The messenger RNA (mRNA) levels of the functional genes in HSCs (ie, seprase, osteonectin, and tenascin-C), quantitated by real-time quantitative polymerase chain reaction, and the density of peritumoral Foxp3+ T-regulatory cells (Tregs) and CD68+ macrophages (MΦ), assessed immunohistochemically in tissue microarray sections, were positively correlated with the density of peritumoral activated HSCs. The density (P = .007 for recurrence-free survival [RFS] and P =.021 for overall survival [OS]) and functional genes (seprase, P = .001 for RFS; osteonectin, P = .007 for RFS and P =.021 for OS) of peritumoral activated HSCs independently contributed to high recurrence or death rates, as did peritumoral Tregs or MΦ. Moreover, peritumoral HSCs were related to more early recurrences. It is important to note that the density of peritumoral activated HSCs, in combination with seprase and osteonectin mRNA or density of Tregs and MΦ, might predict prognoses more effectively.
The comprehension skills of children learning English as an additional language
Authors: Burgoyne K. , Kelly (née Hutchinson) J. M. , Whiteley H. E. , Spooner A.
Published: March 2009

Background Data from national test results suggests that children who are learning English as an additional language (EAL) experience relatively lower levels of educational attainment in comparison to their monolingual, English‐speaking peers.

Aims The relative underachievement of children who are learning EAL demands that the literacy needs of this group are identified. To this end, this study aimed to explore the reading‐ and comprehension‐related skills of a group of EAL learners.

Sample Data are reported from 92 Year 3 pupils, of whom 46 children are learning EAL.

Method Children completed standardized measures of reading accuracy and comprehension, listening comprehension, and receptive and expressive vocabulary.

Results Results indicate that many EAL learners experience difficulties in understanding written and spoken text. These comprehension difficulties are not related to decoding problems but are related to significantly lower levels of vocabulary knowledge experienced by this group.

Conclusions Many EAL learners experience significantly lower levels of English vocabulary knowledge which has a significant impact on their ability to understand written and spoken text. Greater emphasis on language development is therefore needed in the school curriculum to attempt to address the limited language skills of children learning EAL.
Polymer science applied to petroleum production
Authors: Lucas Elizabete F. , Mansur Claudia R. E. , Spinelli Luciana , Queirós Yure G. C.
Published: March 2009

The science of polymers, more specifically, synthesis, characterization, and physicochemical properties in solutions, has wide application in the petroleum industry, which uses polymers as components of fluids or additives to correct problems that affect oil production and/or increase production costs. Polymers are utilized during all phases, from drilling to treatment of oil and water. Research on the synthesis of polymers and their respective characterization aims to develop new molecules, with controlled structures, for various applications, having one or more objectives, namely: (1) to enhance operating efficiency; (2) to reduce costs; and (3) to elucidate mechanisms of action that can help in the development of new technologies. The evaluation of the physicochemical properties of a polymer in solution in many cases permits establishing useful correlations between its properties and performance in a specific application, besides providing insight into the mechanisms inherent in the production system, as is the case of stabilization of asphaltenes. Our research group has applied the knowledge of polymer science to the petroleum industry, focusing on the following functions: viscosification, inhibition of clay swelling, formation of filter cake, drag reduction, divergence, modification of wax crystals, stabilization of asphaltenes, emulsification, demulsification, and cleaning of solids systems contaminated with petroleum, among others.
Hydrophobicity recovery of corona-modified superhydrophobic surfaces produced by the electrospinning of poly(methyl methacrylate)-graft-poly(dimethylsiloxane) hybrid copolymers
Authors: Swart Morne , Mallon Peter E.
Published: March 2009

Superhydrophobicity is dependent on both the surface energy and the texture of the surface. These factors are discussed in terms of a series of electrospun poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) copolymers with different poly(dimethylsiloxane) (PDMS) content. These copolymers are synthesized via conventional free radical copolymerization of methyl methacrylate (MMA) and monomethacryloxypropyl-terminated PDMS macromonomers. It is shown how these copolymers can be electrospun to produce copolymer fibers with diameters in the 100-1000 nm range. The effect of the copolymer composition (and hence the surface energy) and the electrospinning tip-to-collector distance (TCD) on the fiber morphology is discussed. The surfaces produced by the electrospinning process show superhydrophobic properties where the preferential surface segregation of the PDMS component is combined with the roughness of the fiber surface. The surface energy of the fibers is varied by variation of the PDMS content in the copolymers as well as by post-spinning modification with corona discharge. The hydrophobicity of the surfaces shows a greater dependence on the PDMS content than on the average fiber diameter. After exposure of these fiber surfaces to corona discharge, the initial superhydrophobic surfaces become easily wettable despite the fact that much of the surface roughness is maintained after exposure. The samples show the phenomena of hydrophobocity recovery after corona exposure. The rate and extent of this recovery depends on the PDMS content and the corona exposure time. Despite the recovery, scanning electron microscopy (SEM), swelling measurements, and confocal Raman spectroscopy show that permanent surface changes have taken place. The surfaces do not recover to their original superhydrophobic state.
Characteristics of Polymer Wear
Authors: Steijn RP
Published: March 2009

In this paper polymer wear is examined by a consideration of key phenomena occurring at the interface such as the formation of transfer films, metal pick-up, and surface melting. The significance of these aspects is discussed. Also, the concept of abrasive wear is described in terms of the damage done to plastic surfaces. The use of scanning electron microscopy (SEM) in elucidating the nature of polymer wear is well demonstrated.
Test Methods for Automotive and Truck Friction Materials
Authors: Rhee SK , Schwartz HW
Published: March 2009

Properties desired of ideal friction materials include high and stable friction, long durability, and no noise. These properties are determined by field testing using actual vehicles. However, evaluating all experimental friction materials by field testing would be very impractical. Thus friction materials are screened by various laboratory test methods prior to field testing. Laboratory test methods may include vehicles and various types of brake dynamometers. Ideally, results obtained from laboratory testing should be consistent with results obtained from field testing. In reality, however, correlations between laboratory testing and field testing may turn out to be good or poor depending on the equipment and test procedure selected as well as the property to be determined. Relative comparisons between friction material samples can be obtained by using a given test procedure on a selected piece of equipment. This paper describes and discusses various types of test equipment and procedures used for evaluating automotive friction materials.
Full-Scale Testing of Wood Structures
Authors: Tuomi RL
Published: March 2009

Testing full-scale structures is a means to understanding how completed structures perform. Unfortunately, few guidelines exist to aid engineers engaged in such evaluation. Many test procedures are equally applicable to complete structures regardless of the construction material. However, wood possesses many unique properties that must be considered. Tests were conducted on a variety of wood structures. Alternate test methods were developed based upon the locations where tests were performed, which included laboratory tests, field tests with close support, and field tests in remote areas with a minimum of support facilities. These experiences may be useful to engineers confronting similar test situations.
Correlation of Load Testing with Design
Authors: Raths CH , Guedelhoefer OC
Published: March 2009

Laboratory load testing of structures can serve as an extension of the engineer's usual analytical tools. Utilization of load testing to verify structural capacities requires prior field investigations of the structure, study of related plans and specifications, analytical investigations of the structure, and prudent planning of laboratory specimens. The results of laboratory testing combined with analytical procedures provide economical solutions to otherwise complex problems and can lead to the use of safety factors less than would typically be employed for usual design.
Instrumentation and Testing of a Full-Scale Masonry Structure
Authors: Colville J
Published: March 2009

The construction, instrumentation, and loading procedures used in testing a two-story single bay load bearing brick masonry structure are described. In particular, several difficulties encountered during the test program are presented and discussed to assist future studies dealing with the testing of large-scale structures.
The Use of Full-Scale Testing for Establishing and Validating Structural Performance Requirements
Authors: Yancey CWC
Published: March 2009

Two test programs performed by the National Bureau of Standards (NBS) in 1970 and 1971 on wood-framed houses are discussed as cases in point of the use of full-scale testing for establishing and validating structural performance requirements.

In one study, field tests were conducted on an as-built single-family detached house to measure its deflection characteristics under lateral loading. The test data were used to determine whether the drift limitations required in the design of medium- and high-rise buildings are applicable to low-rise buildings. A series of tests was conducted to determine the stiffness of the house when subjected to simulated wind loading. Load was applied alternately at the second floor level and at the eave line of the two-story house. Horizontal and vertical movements of the building were measured at discrete points on the two levels, for the two loading applications and superposition was used to determine the combined effect. As a result of the two test series, it was concluded that: “The measured second-story drift for the house was considerably less than that derived using the drift limits specified for medium- and high-rise buildings in most areas of the United States.”

In the second study, a series of laboratory tests was conducted on a 3.7-m wide by 18.3 m long (12-ft wide by 60-ft long) factory-built housing module. The tests were to determine the strength and stiffness of a typical wood-frame housing unit and to provide baseline data against which the performance of less traditional construction could be compared. Four of the six tests in the series involved the application of lateral load: (1) monotonic racking, (2) repeated racking, (3) reversals of racking, and (4) racking of capacity. Load was applied perpendicular to the long walls at the eave line of the one-story module using a series of hydraulic jacks to simulate the effects of either wind or earthquake loading. Horizontal and vertical displacements were measured at a number of discrete points. The measured response at various design load levels was compared to the limit states specified in design criteria prepared by NBS for the U.S. Department of Housing and Urban Development's (HUD) Operation Breakthrough. Based on an analytical model used to condition the test results, it was concluded that 1.01 kN/m2 (21 psf) was the maximum static wind pressure at which the housing system could satisfy the conventional drift limitation (that is, h/500, where h connotes height above ground level) applied to medium- and high-rise buildings.
Conclusions from July 1976 Engineering Foundation Conference in Rindge, N.H., on Full-Scale Structural Testing
Authors: Longinow A , Schriever WR
Published: March 2009

During the week of 18–23 July 1976, an Engineering Foundation Conference on Full-Scale Structural Testing was held at Franklin Pierce College in Rindge, N.H. It was organized by members of the joint American Society of Civil Engineers' Research Council of Performance of Structures/American Society for Testing and Materials Committee E06 on Performance of Building Constructions (ASCE's RCPS)/ASTM (E06) Committee for Developing a Guide to Professional Practice for Load Tests of Buildings. The conference was partly intended to provide further input for the development of this guide. Many facets of testing of structures were covered during the conference. This included historic aspects of buildings and structures, proof testing of structures including nuclear power plant containment, and existing opportunities for full-scale structural testing. The purpose of this paper is to summarize the conference and to present conclusions pertinent to the subject symposium and as a possible input to the Guide to Professional Practice.
Skyline Plaza North (Building A-4)—A Case Study
Authors: Dixon DE , Smith JR
Published: March 2009

The dynamic collapse of a portion of Building A-4 of the Skyline Plaza Project at Bailey's Crossroads, Va., predicated an extensive investigation of the remaining structure to determine its salvageability. As part of this investigation two types of load tests were performed. Column shear load tests were made in a portion of the structure which was being demolished. These tests were performed to estimate the shear capacity of the flat plate slabs at the columns. Basically, the tests involved isolating the test area around the column by saw cutting the concrete slab. The isolated slab section was loaded in increments until failure using eight post-tensioning rams reacting against the column two floors down. Load-deflection data were used to compute the appropriate shear value.

Several static load tests of the slabs were also performed. These tests utilized the loading criteria given in Chapter 20 of the American Concrete Institute's (ACI) 318-71, “Building Code Requirements for Reinforced Concrete.” Water was used for the required loads with the depth of water and deflection of the slab under load monitored by remote instrumentation. In several cases the loaded areas were more than one-half of the total floor slab area.
Disposal Systems for Oil Recovered from Marine Spills
Authors: Hansen WG , Ross DE , Sinclair JR
Published: March 2009

An on-going study sponsored by the U.S. Coast Guard, Office of Research and Development, is being conducted by SCS Engineers to assess the capabilities and shortcomings of existing disposal systems for oils and oil-debris mixtures recovered from spills. Research objectives are to provide a comprehensive description of existing collection, storage, transfer, treatment, and disposal equipment for possible Coast Guard procurement and to conceptualize needed new equipment and systems for Coast Guard-sponsored research and development.

Project results indicate that developed systems have been designed for specific environmental and debris conditions and may not provide the flexibility for the various situations experienced during Coast Guard operations. Yet equipment is available that can be included in general systems for disposal of oil spill debris under a wide variety of environmental conditions. Seventeen systems utilizing such equipment are defined and assessed in terms of on-site capabilities, deployability, cost, and other factors.
Selection of Oil Spill Landfill Disposal and Temporary Storage Sites Along the Beaufort Sea Coast
Authors: Robson W , Blackall PJ
Published: March 2009

A study was performed to locate landfill disposal and temporary storage sites for oiled debris from sand and shingle beaches along the Beaufort Sea Coast from the Alaska-Yukon border to Cape Bathurst. Approximately 217 landfill disposal sites and 223 temporary storage sites have been located. These sites are shown on 1:150 000 scale strip maps and on 1:20 000 to 1:70 000 scale aerial photographs in the report.

This study involved establishing guidelines for site selection, design, construction, and reclamation for landfill disposal sites, temporary storage sites, and access roads. Limitations on construction, utilization, and reclamation due to seasonal problems with terrain stability, logistics support, and cost effectiveness were considered. All of the sand and shingle beaches in the study area were identified using aerial photographs, and these beaches are shown on 1:150 000 scale strip maps. In addition, alternative or novel landfill disposal and temporary storage techniques are reviewed.
Refinery Oily Waste Treatment and Disposal Techniques and Their Potential Application to Oil Spill Debris
Authors: Knowlton HE , Rucker JE
Published: March 2009

Industry experience with handling of refinery oily wastes has shown that, following all feasible recovery of the oil, landfarming offers the most environmentally acceptable and most economic optimum for treatment and disposal. The use of both landfarming and composting for oil spill disposal appears to be site specific, but both techniques should be considered in evaluating disposal alternatives.
Historical Consideration of Interspecies Relationships in Toxicity Assessment
Authors: Zapp JA
Published: March 2009

The survival of earliest man depended on recognition and avoidance of those plants and animals which were posionous by contact or ingestion. But early man also found that poisonous plants and animals could be used to advantage in hunting and in killing his enemies. References to poisoned arrows are found in both the Old Testament and the early writings of Homer.

Man's earliest knowledge of toxicology came from direct observation and experiments on man. When, at a later period, experimentation on humans became unpopular and illegal, man experimented on animals such as the dog, cat, and rabbit to gain some insight into probable toxicological effects of substances on man. The transfer of data from one species to another requires extrapolation which, although the techniques have been greatly refined, always embodies a degree of uncertainty. Animal experimentation, however, with the application of arbitrary safety factors, remains the basis on which regulatory agencies reach a decision as to the safety of foods, drugs, cosmetics, pesticides and environmental contaminants. For practical purposes it has worked rather well.
A Critical Comparison of Two Bioconcentration Test Methods
Authors: Bishop WE , Maki AW
Published: March 2009

The potential of a chemical to be bioconcentrated from the aqueous environment into fish tissues is generally determined by the kinetic or plateau method. The experiments reported here were designed to evaluate and compare these two methods directly. The test materials included ethylenediaminetetraacetic acid (EDTA), an anionic surfactant, a nonionic surfactant, and DDT. Bluegill (Lepomis macrochirus) whole-body equilibrium bioconcentration factors (BCF) based on 14C retention were calculated from short-term kinetic experiments and compared with BCF values measured in individual 28-day plateau tests. The bioconcentration factors ranged from essentially zero for EDTA, through very low for the surfactants, to very high for DDT. Over this range, BCF values calculated by the kinetic method compared favorably with those derived from the plateau tests. The bioconcentration potential of a wide variety of chemicals may be adequately described by either approach, the kinetic method having certain operational advantages.
Heavy Metal Resistance in Aquatic Bacterial Isolates
Authors: Seyfried PL
Published: March 2009

Environmental isolates of 260 Pseudomonas aeruginosa strains were studied for resistance to mercury, cadmium, arsenic, and lead. All of the isolates were resistant to 1000 µg/ml of arsenic and lead, and most (97 percent) were resistant to 400 µg/ml of cadmium. The distribution patterns of their susceptibilities to mercury clearly revealed two peaks, and it was found that 54 percent of the environmental isolates were sensitive to mercury at concentrations greater than 10 µg/ml.
Comparison of Heavy Metal Interactions in Acute and Artificial Stream Bioassay Techniques for the Asiatic Clam (Corbicula fluminea)
Authors: Rodgers JH , Cherry DS , Graney RL , Dickson KL , Cairns J
Published: March 2009

Population densities of the Asiatic clam, Corbicula fluminea, in the thermally influenced areas of the New River at the Glen Lyn power plant, Glen Lyn, Va., increased from zero before 1975 to approximately 11 522/m2 by February 1978. Since their establishment, clams in the thermal effluent have served as a source of propagules for clam invasion into other areas of the New River during the warmer seasons.

Copper was more toxic (LC50 = 0.04 ppm) to the clam than zinc (LC50 = 6.04 ppm) or copper-zinc simultaneously (LC50 = 0.05 ppm) in 96-h static bioassays. Ninety-six-h LC50 determinations in artificial stream bioassays were at least one order of magnitude higher when compared with the static test values (the LC50 values for copper and copper-zinc combined were 0.49 and 3.06 ppm, respectively). The LC50 values appeared also to be the effective concentration at which at least 50 percent of the clams demonstrated a gaping response and cessation of filtering activity. Elemental bioaccumulation of copper and zinc was more prevalent in the visceral tissue than in concentrations measured from clam valves or from the water in both laboratory bioassays and field determinations. When copper bioaccumulation in the viscera increased to approximately 275 to 400 ppm, gaping and a lack of filtering activity were evident in 96-h tests. Behavioral mechanisms—cessation of filtering activity and the closure of valves during stress—were considered to be likely factors in producing the higher LC50 values, when compared with other invertebrate responses.