bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compressibility and Shear Characteristics of Radforth Peats
Authors: Landva AO , La Rochelle P 
Published: March 2009

Radforth peat is a term introduced here to describe peats with a negligible content of mineral matter. The Sphagnum peat discussed in this paper consists mostly of fibrous particles such as stems, leaves, fiber hairs, etc.
Outstanding characteristics of Radforth peats are their extremely high compressibility and high rate of creep. The variability of peat is often almost unpredictable, even within an apparently uniform deposit. Predictions of magnitude and rate of settlement are therefore difficult. Frequent disturbed sampling and classification combined with empirical relationships may give better results than infrequent undisturbed sampling, consolidation testing, and theoretical relationships.
Peat fibers affect the geotechnical behavior of peat by providing an internal lateral resistance to shear deformations in the triaxial mode of shear. Since pore pressures reduce this resistance, loading under drained conditions will provide better stability through higher lateral resistance.
The shear strength of peat in ring shear would be virtually unaffected by fiber reinforcement. The behavior of the Escuminac peat in ring shear was surprisingly consistent and gave parameters of c = 2.4 kPa and φ = 27 to 32 deg within a load range of 3 to 50 kPa. These values would be directly applicable in the case of retaining structures on peat, for which triaxial φ-values of 40 to 50 deg, as consistently reported in the literature, could in fact be misleading.
Corrosion-Fatigue Crack Initiation Behavior of Four Structural Steels
Authors: Novak SR 
Published: March 2009

This study was undertaken to investigate the corrosion-fatigue crack initiation (CFCI) behavior of steels with nominal yield strengths from 248 to 1034 MPa (36 to 150 ksi). Notched specimens were exposed to a 3.5% NaCl solution under constant-load-amplitude conditions at a stress ratio R of 0.10 and at a cyclic frequency of 12 cycles per minute (0.2 Hz). Results of crack-initiation life (NI) were characterized in terms of cyclic stress-intensity range normalized relative to notch-tip root radius [(ΔK/√ρ)] and in terms of cyclic-stress range at the notch tip (Δσmax).
Results showed that the CFCI behaviors for the A36, A588-A, A517-F, and V-150 steels investigated were virtually identical. Each steel exhibited a linear relationship of (ΔK/√ρ) versus log NI for cyclic lives from NI ≊ 104 to 3 × 106 cycles, where the latter value reflects a continuous testing period of about 180 days (6 months). All four steels exhibited about the same cyclic-stress range of (ΔK/√ρ) ≊ 207 ± 21 MPa (30 ± 3.0 ksi) at NI = 3 × 106 cycles. No evidence of a CFCI threshold behavior was determined or apparent up to 3 × 106 cycles. Compared with the respective estimated values of fatigue-crack-initiation (FCI) threshold in air [(ΔK/√ρ)th ≊ 448, 552, 758, and 1138 MPa (65, 80, 110, and 165 ksi)], such values of (ΔK/√ρ) for CFCI behavior correspond to degradations of about 54, 62, 72, and 82% for the A36, A588-A, A517-F, and V-150 steels, respectively. The cited values of (ΔK/√ρ) at 3 × 106 cycles were also equivalent to a cyclic-stress range at the notch tip of Δσmax ≊ 234 ± 24 MPa (34 ± 3.4 ksi).
The results show that the CFCI behavior of A36, A588-A, A517-F, and V-150 steels is finite for all current test conditions and is determined by the absolute level of the cyclic-stress range [(ΔK/√ρ) or Δσmax]. Such results are in direct contrast with well-established fatigue behaviors in air, where the FCI threshold level [(ΔK/√ρ)th or (Δσmax)th] varies directly with strength level (σys or σts). Thus, the present results show that, whereas FCI behavior varies directly with strength level, the CFCI behaviors for all four steels studied were virtually identical and occurred independently of strength level.
Crack Growth by Stress-Assisted Dissolution and Threshold Characteristics in Corrosion Fatigue of a Steel
Authors: Endo K , Komai K , Shikida T 
Published: March 2009

Corrosion-fatigue crack growth and the threshold characteristics of a high-tension steel HT55 (σB = 580 MPa) have been investigated in 1% NaCl solution by using an automated microcomputer-controlled K-device.
Crack growth rates are significantly reduced in 1% NaCl solution at 5 Hz and R = 0.1, with a threshold value above the air values. The corrosion-products-induced wedge effect results in a reduced ΔK-value, thereby reducing growth rates. Therefore crack growth rates in 1% NaCl solution exceed those in air, with a lower threshold value than in air when considered in terms of ΔKeff.
Supposing a linear summation hypothesis in terms of ΔKeff given by (da/dN)CF = (da/dN)F + (da/dN)D, the crack growth that proceeds by stress-assisted dissolution (da/dN)D is derived. A proposal to estimate long-term corrosion-fatigue crack growth characteristics is presented, where ΔKeff is assumed to be identical to ΔK since the crack tip is blunted and the crack is much thickened in long-term corrosion fatigue. The long-term corrosion-fatigue crack growth curves are finally derived at various stress cycle frequencies.
Acoustic Emissions in Geotechnical Engineering Practice
Authors: Drnevich VP , Gray RE 
Published: March 2009

Description
The Symposium on Acoustic Emissions in Geotechnical Engineering Practice was held 24 June 1981, during the June Committee Week of the American Society for Testing and Materials in Detroit, Michigan. ASTM Committee D18 on Soil and Rock for Engineering Purposes sponsored the symposium. V. P. Drnevich, University of Kentucky, and R. E. Gray, GAI Consultants, Inc., organized the symposium and served as editors of this publication.
Titanium Alloys in Surgical Implants
Authors: Luckey HA , Kubli F 
Published: March 2009

Description
The symposium on Titanium Alloys in Surgical Implants was held in Phoenix, Ariz., on 11-12 May 1981. Sponsoring the event were ASTM Committee F04 on Medical and Surgical Materials and Devices and ASTM Committee B10 on Reactive and Refractory Metals and Alloys. The symposium chairmen were Hugh A. Luckey, 3M Orthopedic Products, and Fred Kubli, Jr., RMI Company, both of whom also served as editors of this publication.
Aquatic Toxicology and Hazard Assessment: Sixth Symposium
Authors: Bishop WE , Cardwell RD , Heidolph BB 
Published: March 2009

Description
The contents of STP 802 include papers on aquatic toxicology, environmental chemistry, environmental modeling, and aquatic hazard assessment. 35 papers serve in the attempt to bridge the gap between laboratory and field results and to model of study the behavior of chemicals of organisms in complex environments.
Elastic-Plastic Fracture: Second Symposium, Volume II Fracture Resistance Curves and Engineering Applications
Authors: Shih CF , Gudas JP 
Published: March 2009

Description
Two separate volumes comprise STP803. The papers in these two volumes have been grouped into six topic areas including elastic-plastic crack analysis, fully plastic crack and surface flaw analysis and correlation, engineering applications, test methods and geometry effects, and cyclic plasticity effects and material characterization.
Pesticide Formulations and Application Systems: Third Symposium
Authors: Kaneko TM , Akesson NB 
Published: March 2009

Description
15 papers address: the use of entomopathogens to control insects; the effects of formulation and aerial application techniques on microbial insecticides; laboratory sprayers used to evaluate the compatibility of tank mixes; effective control of aquatic pests; and selection of appropriate carriers for water-dispersible granules.
Drop-Weight Test for Determination of Nil-Ductility Transition Temperature: User's Experience with ASTM Method E 208
Authors: Holt JM , Puzak PP 
Published: March 2009

Description
STP 919 addresses the user’s experience with the drop weight test, ASTM standard E 208, which determines the nil ductility transition temperature of ferritic steels. The four broad topics of this book are: unusual material behavior; advantages of the test including correlations with service, other tests, or both; Shortcomings of the method; and unique testing equipment and experimental techniques.
The prevalence and characteristic features of cyclicity and variability in Cushing's disease
Authors: Alexandraki Krystallenia I , Kaltsas Gregory A , Isidori Andrea M , Akker Scott A , Drake William M , Chew Shern L , Monson John P , Besser G Michael , Grossman Ashley B 
Published: March 2009

ObjectiveCyclical Cushing's syndrome may render the diagnosis and management of Cushing's disease difficult. The aim of the present study was to investigate the prevalence of cyclicity and variability in patients with Cushing's disease, and to identify putative distinctive features.DesignRetrospective case-note study.MethodsWe analysed the case records of 201 patients with Cushing's disease in a retrospective case-note study. Cyclicity was considered as the presence of at least one cycle, defined as a clinical and/or biochemical hypercortisolaemic peak followed by clinical and biochemical remission, followed by a new clinical and/or biochemical hypercortisolaemic peak. The fluctuations of mean serum cortisol levels, as assessed by a 5-point cortisol day curve, defined the variability.ResultsThirty (14.9%; 26 females) patients had evidence of cyclicity/variability. ‘Cycling’ patients were older but no difference in sex or paediatric distribution was revealed between ‘cycling’ and ‘non-cycling’ patients. The median number of cycles was two for each patient, and 4 years was the median intercyclic period. A trend to lower cure rate post-neurosurgery and lower adenoma identification was observed in ‘cycling’ compared with ‘non-cycling’ patients. In multivariate analysis, older patients, longer follow-up, female sex and no histological identification of the adenoma were associated with an increased risk of cyclic disease.ConclusionsThis large population study reveals that cyclicity/variability is not an infrequent phenomenon in patients with Cushing's disease, with a minimum prevalence of 15%. Physicians should be alert since it can lead to frequent problems in diagnosis and management, and no specific features can be used as markers.
Merits and pitfalls of mifepristone in Cushing's syndrome
Authors: Castinetti F , Fassnacht M , Johanssen S , Terzolo M , Bouchard P , Chanson P , Do Cao C , Morange I , Picó A , Ouzounian S , Young J , Hahner S , Brue T , Allolio B , Conte-Devolx B 
Published: March 2009

ObjectiveMifepristone is the only available glucocorticoid receptor antagonist. Only few adult patients with hypercortisolism were treated to date by this drug. Our objective was to determine effectiveness and tolerability of mifepristone in Cushing's syndrome (CS).DesignRetrospective study of patients treated in seven European centers.MethodsTwenty patients with malignant (n=15, 12 with adrenocortical carcinoma, three with ectopic ACTH secretion) or benign (n=5, four with Cushing's disease, one with bilateral adrenal hyperplasia) CS were treated with mifepristone. Mifepristone was initiated with a median starting dose of 400 mg/day (200–1000). Median treatment duration was 2 months (0.25–21) for malignant CS, and 6 months (0.5–24) for benign CS. Clinical (signs of hypercortisolism, blood pressure, signs of adrenal insufficiency), and biochemical parameters (serum potassium and glucose) were evaluated.ResultsTreatment was stopped in one patient after 1 week due to severe uncontrolled hypokalemia. Improvement of clinical signs was observed in 11/15 patients with malignant CS (73%), and 4/5 patients with benign CS (80%). Psychiatric symptoms improved in 4/5 patients within the first week. Blood glucose levels improved in 4/7 patients. Signs of adrenal insufficiency were observed in 3/20 patients. Moderate to severe hypokalemia was observed in 11/20 patients and increased blood pressure levels in 3/20 patients.ConclusionMifepristone is a rapidly effective treatment of hypercortisolism, but requires close monitoring of potentially severe hypokalemia, hypertension, and clinical signs of adrenal insufficiency. Mifepristone provides a valuable treatment option in patients with severe CS when surgery is unsuccessful or impossible.
Early Weight Gain Predicts Retinopathy in Preterm Infants: New, Simple, Efficient Approach to Screening
Authors: Hellström Ann , Hård Anna-Lena , Engström Eva , Niklasson Aimon , Andersson Eva , Smith Lois , Löfqvist Chatarina 
Published: March 2009

BACKGROUND. The risk for sight-threatening retinopathy of prematurity is predicted by using gestational age and/or weight at birth. All infants below a threshold undergo serial ophthalmologic examinations for identification of those who would benefit from treatment (∼10%). We hypothesized that factoring in postnatal weight gain could identify children at risk for sight-threatening retinopathy of prematurity more specifically and earlier.
METHODS. Weekly weights from birth to postmenstrual week 36 were retrospectively entered into a surveillance system that gave an alarm when the rate of weight gain decreased to a certain level. For all children (N = 354) screened and/or treated for retinopathy of prematurity at Sahlgrenska University Hospital in 2004–2007, weekly weights were recorded. One child was excluded because of known nonphysiologic weight gain (hydrocephalus).
RESULTS. For 127 (36%) of 353 children, no alarm was given; for 40%, alarm at low risk was given after postmenstrual week 32. None of those children developed retinopathy of prematurity requiring treatment. Of the remaining 24% of children who received alarm at high or low risk before 32 postmenstrual weeks, 41% developed proliferative retinopathy of prematurity and 29% were treated because of sight-threatening disease. The median time from alarm to treatment was 9 weeks.
CONCLUSIONS. The weight, insulin-like growth factor, neonatal retinopathy of prematurity algorithm detected early 100% of infants who developed retinopathy of prematurity requiring treatment and correctly predicted the majority who did not require treatment. With this simple postnatal evaluation, costly stressful eye examinations can be markedly reduced (∼75% of infants). In addition, early identification of children at risk may lead to the initiation of interventions and possibly prevent sight-threatening retinopathy of prematurity.
Morphology and Electrochemistry of Hydrothermally Prepared LiMnPO4
Authors: Allen Jan L. , Jow T. Richard , Wolfenstine Jeff 
Published: March 2009

ABSTRACTIn this study, we explored the synthesis of LiMnPO4 through hydrothermal methods using urea as the hydroxide ion source. The hydrothermally prepared LiMnPO4 was examined through x, ray diffraction, microscopy, surface area and electrochemical measurements. Small crystallites were formed and significant agglomeration of particles was observed. The effect of additives to control nucleation and growth of the LiMnPO4 is reported. None of the attempted additives led to the desired morphology. At a C/5 discharge rate, a capacity of about 53 mAh/g was observed for a carbon coated sample of hydrothermally prepared LiMnPO4.
Effect of Particle Size of Mo Solid Solution on Hardness of Mo5SiB2/Mo-Based Alloys
Authors: Yoshimi Kyosuke , Kondo Yusuke , Maruyama Kouichi 
Published: March 2009

AbstractThree kinds of Mo-Si-B ternary alloys and a 1 at.% Al added Mo-Si-B alloy with the compositions near Mo-8.7 at.% Si-17.4 at.% B that is in the Mo5SiB2 and Mo two-phase compositional region were produced by Ar arc-melting followed by the heat treatment at 1800 °C for 24 h. These alloys have the characteristic fine microstructure composed of small Mo solid solution (Moss) particles in the Mo5SiB2 (T2) matrix with the primary phase (Moss or T2 depending on composition). The volume fraction of the Moss particles ranges from 25.5 to 30.5 % and its average size from 3.0 to 6.4 μm in the fine microstructure of the alloys. Micro cracks were introduced by Vickers hardness tests into the microstructures, and their propagation is disturbed by the small Moss particles. Thus, each hardness value seems to relate to the cracking behavior around each indent. On the other hand, Vickers hardness values do not show correlation with the volume fraction of the Moss particles, but clearly decrease with increasing the average particle size of Moss. Therefore, it should be concluded that the increase in the particle size of Moss could enhance the toughness of the Mo5SiB2/Mo-based alloys effectively by ductile phase toughening.
True Matching of Bit and Multidiameter String Tools Delivers Optimized Drilling Performance
Authors: Barton Steve , Clegg John 
Published: March 2009

Abstract
The increased use of hole opening tools remote from the drill bit has led to a critical need to understand the interaction between the drill bit and the hole opening tool itself. Problems that can result from improper matching include vibration, inability to open hole, mechanical damage to string tools or to the bit, and sub-optimal drilling performance.
This paper explores the theoretical relationship between bit and reamer and modeling the relative agressivity and stability of both tools, building on already established indices for predicting and comparing the performance of bits. It also considers stabilization of the hole opening tool using both concentric and eccentric devices. It describes theoretical modeling of the vibration behavior of the assembly. It then describes field validation of the above using a unique downhole data recording device, located at various key points in the BHA and drill string.
Finally, the paper will review a number of case studies and demonstrate a linkage between the theoretical analysis, the measured validation, and actual field results. These relate to a variety of directional applications including vertical rotary, directional motor and rotary steerable, and demonstrate reduced vibration, improved hole quality and hole opening performance, superior penetration rates, and overall significantly reduced drilling costs.
Under-Rig-Floor Open Hole Logging in the Gulf of Thailand: Operational Implementation of the Oil Industry's First Simultaneous Open Hole Wireline Logging and Drilling Operation
Authors: Upchurch Eric R. , Laoamornpanich Thaveesub 
Published: March 2009

Abstract
Chevron Thailand, on average, drills 12000' MD / 8200' TVD wells in about 4.5 days. The factor that most contributes to this level of performance is the "offlining" of as many drilling rig activities as possible. In our drilling operation, almost all pipe handling and cementing operations are performed offline (i.e., off the critical operations path and therefore simultaneous to other activities on the rig). We have now taken the next logical step in performing offline operations. In May 2007, Chevron Thailand introduced the world's first simultaneous open hole wireline logging and drilling operation on Seadrill RT-7 (a tender-assist drilling rig), and presently is deploying the same system on additional tender-assist and jack-up rigs.
This paper is the second in a series of two that describe the engineering design and operational implementation of the tools and techniques necessary to make offline open hole wireline logging a reality. The first paper1 in this series details the engineering design aspects, and the resultant benefits, of this paradigm-changing logging system. This second paper describes the processes that were used to implement the system, along with the inherent risks and benefits of each phase of the implementation. Implementing radically new processes such as this into pre-existing drilling systems significantly increases the risk for technical failure, well control incidents and personnel injury. This paper details the processes that were developed for avoiding all three. In the case of this new technology, our phased approach to implementation has resulted in smooth, incident-free introductions to the various rig sites. The benefits of this new system and our method for implementing it incident-free are paying significant dividends to Chevron Thailand.
Analysis of Hook Load Forces During Jarring
Authors: Newman Kenneth R. , Procter Ray 
Published: March 2009

Abstract
Twice in a year, on opposite sides of the world, drilling rigs collapsed after prolonged jarring operations. This paper documents the analysis performed to determine if the jars could generate enough force to overload the rig structure.
Data from the drilling logs was taken at time intervals of 10 seconds or greater. These large time intervals did not allow the peak shock loads to be recorded. The rig instrumentation or sampling rate tends to damp out these peak shock loads. Thus, during jarring operations the loading can be significantly different than that displayed by the rig instrumentation.
A dynamic finite element jarring analysis was done for both of these cases. This analysis calculates the loads along the drill string before and after the jar is released. The impact load travels up and down the string at the speed of sound in steel, causing spikes in the surface loads. To simulate these dynamic loads the model is run with a time interval of 100th of a second. This allowed the loading seen by the rig structure to be simulated. The input parameters and modeling results from one of these analyses are presented in the paper.
Pattern Recognition-Based Remaining Useful Life Estimation of Bottomhole Assembly Tools
Authors: Garvey D. R. , Baumann J. , Lehr J. , Hines J. W. 
Published: March 2009

Abstract
This paper describes a new pattern recognition based system for estimating the remaining useful life (RUL) of bottomhole assembly (BHA) tools.
Modern drilling equipment operates in increasingly severe environments, with downhole temperatures in excess of 200°C and high impact vibration events being common. Additionally, rig operators are asking tools to perform mission profiles that have previously been impossible, thereby increasing the stress on the downhole tools. All the while, clients are beginning to contractually demand high reliability to help them prevent costly downhole failures and ensure profitability.
Current periodic maintenance practices are proving to be insufficient or cost-intensive to meet these new challenges. Because of this, industry is shifting toward simple condition-based maintenance, which uses design guidelines and rough operational thresholds to assess individual tool health. While there is value in the latter approach, there is a large amount of tool performance and environmental data collected during operation that has yet to be effectively incorporated into the health assessment process. This paper addresses this shortcoming by using the available data to infer the RUL of individual tools.
Using "real world" data collected from a rotating steering system tool, the prognosis system is shown to be able to predict the RUL of individual tools with an accuracy ranging from 0.88 to 8.76 hours over three test sets.
The developed system will allow service providers to make more agile maintenance decisions and provide operators the means to incorporate reliability into the well planning and operations processes, enabling monetary savings for both parties.