bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous impact/abrasion testing: Influence of testing parameters on wear behaviour
Authors: Badisch E , Kirchgaßner M , Franek F 
Published: March 2009

In many fields of industry, erosion is the dominant wear mechanism that reduces the lifetime of costly machine parts such as crushers, hammer bars, or cutting edges. Particles of specific mechanical and geometrical properties hit the surface with a certain energy and, under different angles of impact, cause abrasion and surface fatigue, or, in the case of high single particle impact energy, immediate damage by exceeding the rupture strength. Different types of wearfacing alloy layers applied through welding are used to protect exposed surfaces. The structure of state-of-the-art welding alloys is always based on multi-phase systems containing effective hard phases based mainly on borides and carbides of W, Cr, Nb, and others. Within this work the so-called continuous impact abrasion test was established to compare different wearfacing alloys as described above and to develop a relation between parameters of the tribological system and properties of multi-phase materials. In the first step, morphology, energy, and size of the abrasive particles were varied and applied onto two different Fe-based wearfacing alloys. Observations on the phenomena of wear on the test samples accompanied by a quantitative evaluation of volumetric wear loss finally resulted in defining a model that enables a prognosis oriented consideration of wear. It was found within this study that wear phenomena in the microstructure have to be clearly differentiated according to the total energy applied and the impact energy of a single particle.
An exploration of the elastohydrodynamic— hydrodynamic transition through film thickness measurements in rolling point contacts
Authors: Dalmaz G , Chaomleffel J-P , Vergne P 
Published: March 2009

The numerical solution of the elastohydrodynamic lubrication (EHL) problem is often presented in charts where dimensionless parameters and asymptotic relationships are used. Among them, the so-called isoviscous rigid asymptote is especially interesting because it defines the transition between elastohydrodynamic and hydrodynamic regimes, or between piezoviscous—elastic and isoviscous—rigid problems, respectively. In other respects, the combination of moderate contact pressures (i.e. moderate piezoviscosity, low normal load, and/or large radii of curvature) and high viscosity and speeds (i.e. high hydrodynamic effect) is quite often found in working mechanisms, for instance in most flange contacts in roller bearings. Surprisingly, only a few papers have analysed and discussed these operating conditions. Based on experimental results obtained in the range of the Moes parameters 15< L<50 and 2< M<160 for pure rolling circular point contacts, the aim of this work is first to show how film thickness distributions are affected when the piezoviscous elastic to isoviscous rigid transition is approached. In this context, the relative values taken by the central and minimum film thicknesses will be particularly studied. The second objective is to compare our results with those predicted by elastohydrodynamic and hydrodynamic solutions for non-conformal contacts found in the literature. Finally, the exploration of mild EHL is dealt with and a former publication in which electrohydrodynamic very thin films and highly loaded thick film regimes were studied is completed.
A tribological day
Authors: Dowson D 
Published: March 2009

Most tribologists are concerned with engineering applications of their skills, yet little recognition is given to the many illustrations of effective solutions to friction, wear, and lubrication problems evident in our everyday lives. This view will be supported by examples encountered by most of us in a single day, with an open encouragement to all to add to the list. Several of these examples are embedded in biotribology and many were reported before either tribology, in 1966, or biotribology, in 1970 and 1973, was formally defined. It is hoped that this account of a typical … Tribological day in the life of … will expose some of the fascinating examples of tribology all around us.
“Counting Your Customers” One by One: A Hierarchical Bayes Extension to the Pareto/NBD Model
Authors: Abe Makoto 
Published: March 2009

This research extends a Pareto/NBD model of customer-base analysis using a hierarchical Bayesian (HB) framework to suit today's customized marketing. The proposed HB model presumes three tried and tested assumptions of Pareto/NBD models: (1) a Poisson purchase process, (2) a memoryless dropout process (i.e., constant hazard rate), and (3) heterogeneity across customers, while relaxing the independence assumption of the purchase and dropout rates and incorporating customer characteristics as covariates. The model also provides useful output for CRM, such as a customer-specific lifetime and survival rate, as by-products of the MCMC estimation. Using three different types of databases—music CD for e-commerce, FSP data for a department store and a music CD chain, the HB model is compared against the benchmark Pareto/NBD model. The study demonstrates that recency-frequency data, in conjunction with customer behavior and characteristics, can provide important insights into direct marketing issues, such as the demographic profile of best customers and whether long-life customers spend more.
Effects of Quetiapine on Sleep in Nonpsychiatric and Psychiatric Conditions
Authors: Wine Jessica N , Sanda Christina , Caballero Joshua 
Published: March 2009

Objective: To evaluate the use of immediate-release quetiapine for the treatment of insomnia. Data Sources: Pre-MEDLINE and MEDLINE were searched (1966 to October 2008) using the terms quetiapine, sleep, insomnia, and antipsychotics. Study Selection and Data Extraction: All studies and case reports evaluating insomnia as a primary endpoint were reviewed. Data Synthesis: The role of quetiapine for improving sleep in various patient populations is uncertain. Quetiapine has moderately sedative properties, and closes used in treatment of insomnia have ranged from 12.5 to 800 mg. Results of clinical trials and observations in case studies have revealed possible beneficial effects of quetiapine on several subjective and objective sleep parameters. In most studies, significant improvements in sleep were found in areas of total sleep time, sleep efficiency, and subjective sleep scores. However, some of these results may not be clinically significant. Also, quetiapine has been found to have adverse effects such as periodic leg movements, akathisia, and metabolic complications. Additionally, changes in rapid eye movement (REM) and percentage of REM sleep have been noted in different populations and need further study. Despite quetiapine's sedative properties, current data do not appear to support its use as first-line treatment for sleep complications. However, it may be useful for treatment of insomnia in patients with psychiatric disorders (eg, bipolar, schizophrenia) who do not respond to primary or secondary treatments. Conclusions: Further studies are needed to define the placement, dose, and adverse effects of quetiapine for the treatment of sleep problems.
Midodrine and Octreotide in Treatment of Cirrhosis-Related Hemodynamic Complications
Authors: Karwa Rakhi , Woodis C Brock 
Published: March 2009

Objective: To review studies evaluating the use of midodrine and octreotide in hemodynamic complications of cirrhosis, including ascites and hepatorenal syndrome. Data Sources: Searches of MEDLINE (1966–September 2008) and EMBASE (1974–September 2008) were conducted using the terms midodrine, octreotide, hepatorenal syndrome, ascites, cirrhosis, and paracentesis-induced circulatory dysfunction. Literature review was limited to English-language, human studies. Study Selection and Data Extraction: Studies identified from data sources were considered for review. Studies were excluded if primary therapy involved any of the following: transjugular intrahepatic portosystemic shunt procedure, medications other than midodrine or octreotide, or patients included for treatment or prevention of portal hypertension and/or variceal bleeding. Pharmacokinetic/pharmacodynamic studies and studies using retrospective data collection were excluded. Seven studies were included in this review. Data Synthesis: Midodrine and octreotide in combination or alone have shown conflicting results for systemic and renal hemodynamics and renal function in patients with cirrhosis-related complications. Patients with ascites being treated with midodrine, alone or in combination with octreotide, showed significant changes in systemic hemodynamics, without a correlating change in renal perfusion. Studies comparing the use of midodrine with use of albumin for the prevention of paracentesis-induced circulatory dysfunction (PICD) showed no incidence of PICD in either treatment group. In hepatorenal syndrome, patients using midodrine with octreotide showed significant changes in systemic hemodynamics and improvements in renal perfusion. This regimen's effect on survival is yet to be determined, Conclusions: Available evidence shows inconsistent results for the effectiveness and safety of midodrine and octreotide use in cirrhotic patients. Because of the contradictory results, longer treatment duration and increased number of study participants are necessary to determine the proper use of midodrine and octreotide in these patients.
Probable Amlodipine-Induced Angioedema
Authors: Southward Jessica , Irvine Elizabeth , Rabinovich Marina 
Published: March 2009

Objective: To report a case of angioedema likely associated with amlodipine administration in a patient with a right thalamic hemorrhagic stroke. Case Summary: A 50-year-old female experienced angioedema during hospitalization for s right thalamic hemorrhagic stroke. She had no past history of angioedema and all of her medications were assessed for risk of angioedema. After careful evaluation, case reports linking calcium channel blockers (CCBs) and angioedema led to further examination of amlodipine as a cause. Amlodipine therapy had been initiated 24 hours prior to the development of angioedema, which then resolved 72 hours after discontinuation of the drug. In total, the patient experienced oropharyngeal swelling for 10 days. Discussion: In determining a cause for the patient's angioedema we eliminated genetic, allergic, physically induced, thyroid autoimmune disease-associated, and medication-induced causes. Three case reports describing 7 patients have linked the CCBs verapamil, diltiazem, and nifedipine with angioedema. The onset and resolution of symptoms in our patient were very similar to those seen in other case reports. Application of the Naranjo probability scale found a probable link between amlodipine and angioedema. Conclusions: Although few reports of CCB-induced angioedema exisi, to our knowledge, this is the first reported case to suggest a link between angioedema and amlodipine therapy. Clinicians should consider amlodipine as a potential cause of angioedema.
Effect of “Energy Drink” Consumption on Hemodynamic and Electrocardiographic Parameters in Healthy Young Adults
Authors: Steinke Leah , Lanfear David E , Dhanapal Vishnuprabha , Kalus James S 
Published: March 2009

Background:Energy drinks are frequently purported to improve cognitive function and concentration. However, the cardiovascular effects of these drinks have not been adequately studied.Objective:To determine the cardiac effects of a commercially available, multicomponent energy drink in healthy volunteers.Methods:Fifteen healthy adults were Included in this prospective study. Individuals who had chronic medical conditions, ware on chronic medication, or were pregnant or breast-feeding were excluded. Subjects abstained from caffeine for 48 hours prior to and during the study. In the morning on Day 1 of the study, while subjects were in a fasted state, baseline blood pressure (BP), heart rate (HR), and electrocardiographic (ECG) parameters were measured. Participants then consumed 500 mL (2 cans) of an energy drink and measurements were repeated 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours later. Participants then drank 500 mL of energy drink daily for the next 5 days. Day 1 protocol was repeated on Day 7.Results:On Days 1 and 7, maximum mean systolic BP (SBP), HR, and QTc interval occurred at 4 hours. Maximum diastolic BP (DBP) occurred at 2 hours on Days 1 and 7. Within 4 hours of energy drink consumption, on Days 1 and 7, respectively, SBP increased by 7.9% (p = 0.006) and 9.6% (p < 0.001), HR increased by 7.8% (p = 0.009) and 11.0% (p < 0,001). and QTc interval increased by 2.4% (p = 0.368) and 5.0% (p = 0.052), DBP increased by 7.0% < p = 0.046) and 7.8% (p = 0.063) within 2 hours of energy drink consumption on Days 1 and 7, respectively.Conclusions:Although no significant ECG changes were observed, HR increased 5–7 beats/min and SBP increased 10 mm Hg after energy drink consumption.
Syntactic Language Change in a German Dialect: Replacement or Reanalysis of a Construction?
Authors: Geyer Klaus 
Published: March 2009

Abstract
This article discusses a type of prepositional construction that is highly characteristic for a group of East Franconian dialects, located in the south-eastern part of Germany. The construction expresses local relations and contrasts with the standard German construction as well as with the regional standard of this area. Based on spontaneous spoken dialect material, the article reveals an ongoing process of change: among young adults today not only the standard variant but also occasional hybrid formations are used as replacements for the original, the latter functioning as membership-markers to this dialectal community.
Evaluation of the Ct Parameter for Characterizing Creep Crack Growth Rate in the Transient Regime
Authors: Bassani JL , Hawk DE , Saxena A 
Published: March 2009

An in-depth evaluation of the Ct parameter, which has been proposed for characterizing the creep crack growth behavior under small-scale-creep (transient) to extensive creep conditions, is conducted. The evaluation includes a thorough examination of the assumptions made in the definition of Ct, an experimental evaluation, and a finite-element analysis of a compact specimen used in an actual creep crack growth experiment.
The experimental correlations between da/dt and Ct are extremely encouraging. Ct is interpreted as the stress-power (or energy rate) release rate during crack extension. Under extensive creep conditions, Ct therefore equals C*, which is given in terms of a path-independent integral as well as the stress-power release rate. Under small-scale creep, Ct is shown to characterize the rate of growth of the creep zone. More finite-element analyses and experiments under highly transient conditions are recommended for completing the understanding of the creep crack growth behavior in this regime.
An Advanced Procedure for J-R Curve Testing Using a Drop Tower
Authors: Joyce JA , Hackett EM 
Published: March 2009

An improved method to obtain J-R curves from drop-tower fracture mechanics specimens is described in detail. New features include aluminum absorbers to smooth the load versus time record, a double-capacitance gage to locate the crack initiation point, and an analytic key curve to obtain the J-R curve from a test on a single full-size fracture mechanics specimen. The absorbers are shown to slow the initial loading rate but not to affect the displacement rate near crack initiation or during the ductile tearing portion of the drop test.
Drop-tower J-R curves are obtained for a 3% nickel structural steel and compared with static results and results obtained by earlier test methods.
Correlation of Optical Caustics with Fracture Behavior of High-Strength Steels
Authors: Judy RW , Sanford RJ 
Published: March 2009

Because the optical caustic technique offers unique opportunities for experimental measurement of fracture toughness under conditions where ordinary instrumentation cannot be used, an effort to correlate the size of the caustic with fracture parameters has been undertaken. The materials of interest are a 4340 steel in a range of thicknesses designed to allow plane-strain, plane-stress, and mixed-mode constraint conditions; an intermediate-strength 5% nickel steel with a high degree of fracture resistance; and a lower-strength, ductile high-strength low-alloy (HSLA) steel, A710. Using compact tension specimens and standard K and J-integral testing procedures, the caustics were photographed as fracture tests were conducted.
Experiments showed that there is a clear correlation between the J-integral and the caustic diameter (D) for all three steels. The values did not conform to expected relationships predictable from existing theory for several reasons. In the 4340 steel, the correlation for the three thickest samples was independent of thickness, while the thinnest (plane-stress) sample was distinctly different when the generating circle was contained inside the plastic zone. Under these conditions, the J-D correlation was distinctly different for the other two steels as well. When the generating circle was maintained outside the plastic zone, a single relationship was obtained for all three steels. This behavior is attributed to differences between the steels in plastic flow behavior and slip systems. As a result, the near-field behavior is strongly influenced by factors that have little or no effect on the far-field behavior.
Compression Seals
Authors: Watson SC 
Published: March 2009

The theoretical concept, development stage, and comprehensive field testing in the full-scale use of preformed compression joint seals is discussed and documented.
A history of its early usage, which led to the selection of the necessary properties for quality control of elastomeric vulcanizates, typical configurations, machine installation techniques, use of lubricant adhesives as a companion material, plus the entry of compression seals in both airfield and highway pavements as well as architectural industrial environments, is described.
Some recent research is reported on, and the importance of relating specifications to environmental needs is emphasized.
Future trends, such as mechanical locking of seal elements to joint interfaces, uses of low profile seal elements, development of strip and gland type systems and their current application in bridges and structures, are discussed.
Helicopter Rotor Blades
Authors: Pinckney RL 
Published: March 2009

The development of fiber reinforced resin-bonded structural composite materials has created a new degree of design flexibility for the helicopter engineer. The development and commercial availability of glass fibers, carbon or graphite fibers, and boron fibers, with their attendant widely varying stiffness properties and material densities, enable the specialist both to design his structure to utilize the excellent fatigue properties of the materials available and to design the inherent properties of the material which he intends to use in his advanced VTOL systems.
Filament reinforced epoxy structures are compared with metal structures commonly used for helicopter rotor blades. Test data on several fiber reinforced epoxy materials and development test results of full-sized reinforced epoxy rotor blade segments are given. The manufacturing techniques, quality assurance provisions, and economic considerations of the cost of materials versus component performance improvements are also discussed.
Comparison of R-Curves Determined from Different Specimen Types
Authors: Sullivan AM , Freed CN , Stoop J 
Published: March 2009

Crack growth resistance curves (R-curves) have been obtained by testing center-cracked tension specimens (CCT) of three aluminum alloys, one titanium alloy, and two steels. Direct comparison is possible for four of these alloys with R-curves determined from crackline loaded (CLL) specimens.
Some differences between the two specimens are found in the reported values of Kc. These appear to be a direct consequence of the type of stress-crack length relationship noted during testing. In tough material tested using the CCT specimen, the crack grown first under a rising load but finally continues to extend at a constant load. Since this constant load crack growth marks the end of structural integrity, its recognition is crucial to a rational interpretation of fracture resistance. The CCL specimen type does not discriminate between the changes in crack growth behavior observed for these tough materials. Further, it is shown that fatigue precracking may influence the amount of crack growth prior to instability even though the final value of Kc remains unchanged.
No evidence of variation in the Kc-value with initial crack length has been observed over the range of slit lengths investigated.
Biological Monitoring of the Aquatic Environment
Authors: Weber CI 
Published: March 2009

A nation-wide water quality monitoring network was operated from 1957 to 1968 by a central Federal laboratory in Cincinnati. The network was decentralized in 1968, and the responsibility for its operation was transferred to the regional offices of the Federal Water Quality Administration. Following the creation of the Environmental Protection Agency, an Office of Monitoring was established to provide overall technical coordination of the monitoring program and to standardize methodology and maintain quality control of the data. The responsibility for water quality monitoring in the EPA will be shared by the Office of Monitoring, Office of Air and Water Programs, Office of Enforcement and General Counsel, and Office of Research. Four types of monitoring have been identified—ambient trend monitoring, source monitoring, case preparation monitoring, and research monitoring. The water quality monitoring network of the EPA will consist of 5000 to 10 000 EPA-funded stations and 40 000 to 50 000 stations operated by state and local agencies. The data will be stored in a central EPA computerized system called STORET. The responsibility for quality control and the development, validation and standardization of chemical, microbiological, and biological methodology for water and waste water has been assigned to the Analytical Quality Control Laboratory (AQCL) in Cincinnati.
Water quality is reflected in the species composition and diversity, population density and physiological condition of indigenous communities of aquatic organisms. Biological methodology employed in water quality monitoring in the EPA deals primarily with sample collection, sample processing, counting and identification of aquatic organisms, biomass measurements, measurement of bioaccumulation and biomagnification of pollutants, and biological data processing and interpretation. The AQCL conducts research in all areas of biological methodology for water quality monitoring, develops reference samples for quality control, and conducts agency-wide interlaboratory methods studies. An Agency biological methods manual is in preparation and will be available in 1973.