bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of SASW Phase Angle and Phase Velocity Measurement Uncertainty
Authors: Marosi KT , Hiltunen DR 
Published: May 2004

Abstract
The spectra-analysis-of-surface-waves (SASW) method is a nondestructive test for characterization of the variation with depth of the shear wave velocity of soils. While the testing procedure is well developed, only one preliminary study has investigated measurement uncertainty associated with SASW, and the methods utilized to quantify measurement uncertainty were prohibitive to routine assessment. Knowledge of this uncertainty, and ability to include its assessment in routine testing, would allow for inclusion of SASW results in reliability based design and in assessment of the spatial variability of shear modulus.
In this study, a large sample of test data was collected from two test sites. Characteristic statistics, statistical distribution, and measurement uncertainty were determined for each phase of SASW. Using the empirical statistical properties and measurement uncertainty results as validation criteria, an analytically based uncertainty assessment system was developed.
Specifically, it was shown that SASW phase angle and inverse phase angle typically display a coefficient of variation (COV) of 2 %, and samples appear normally distributed. Further, SASW phase velocity data typically display a coefficient of variation (COV) of 2 %, and the COV for combined phase velocity data is typically 1.5 %. Both phase velocity and combined phase velocity samples appear normally distributed. In addition, it was found that by using a small sample of experimental data and the analytically based process developed in this study, measurement uncertainty of SASW phase angle and phase velocity could be assessed as part of routine testing.
Constraint Correction of Fracture Toughness CTOD for Fracture Performance Evaluation of Structural Components
Authors: Minami F , Arimochi K 
Published: May 2004

Abstract
A correction of CTOD for constraint loss in large-scale yielding conditions is made on the basis of the Weibull stress fracture criterion that eliminates an excessive conservatism in the conventional fracture assessment and material fracture toughness requirement. A CTOD ratio β = δ3P / δWP (&lt;1) is proposed, where δWP is the CTOD of a wide plate component and δ3P is an equivalent CTOD of the fracture toughness specimen at which the toughness specimen gives a compatible Weibull stress with the wide plate. The CTOD ratio β is decreased to a large extent after full yielding of the wide plate component, which is more significant for a high yield ratio YR and a deep surface crack in the wide plate. The Weibull modulus m exerts a marginal influence on β. A case study is presented on the application of the CTOD ratio β to the fracture performance assessment of full-scale column-to-beam connections subjected to cyclic and dynamic loading.
Probabilistic Life Prediction Isn't as Easy as It Looks
Authors: Annis C 
Published: May 2004

Abstract
Many engineers effect “probabilistic life prediction” by replacing constants with probability distributions and carefully modeling the physical relationships among the parameters. Surprisingly, the statistical relationships among the “constants” are often given short shrift, if not ignored altogether. Few recognize that while this simple substitution of distributions for constants will indeed produce a nondeterministic result, the corresponding “probabilities” are often woefully inaccurate. In fact, even the “trend” can be wrong, so these results can't even be used for sensitivity studies. This paper explores the familiar Paris equation relating crack growth rate and applied stress intensity to illustrate many statistical realities that are often ignored by otherwise careful engineers. Although the examples are Monte Carlo, the lessons also apply to other methods of probabilistic life prediction, including FORM/SORM (First/Second Order Reliability Method) and related “fast probability integration” methods.
Scatter in Fatigue Crack Growth Rate in a Directionally Solidified Nickel-Base Superalloy
Authors: Highsmith S , Johnson WS 
Published: May 2004

Abstract
Directional solidification of nickel-base superalloy components for gas turbine rotor blades offers a significant improvement in creep strength while at the same time yielding an anisotropic, heterogeneous microstructure. In such a material, some of the continuum assumptions of linear elastic fracture mechanics begin to break down, and local (microscopic) conditions can lead to significant deviation in fatigue crack growth rate from the global (macroscopic) trend. Fatigue crack life prediction for a large population of fielded components requires a probabilistic treatment of the material fatigue crack growth behavior. A common approach to probabilistic fatigue crack life prediction involves sampling the Paris law coefficients from a large number of crack growth experiments, which can lead to effectively “smoothing” the local intraspecimen variability out of the model. The length scale of variability is discussed as it relates to material microstructure and crack life prediction. Results from fatigue crack growth experiments on a directionally solidified superalloy are presented and spatial variation in the fatigue crack growth rate is examined. Periodicity of the crack growth rate variation is compared with the scale of microstructural heterogeneity.
Predicting Fatigue Life Under Spectrum Loading in 2024-T3 Aluminum Using a Measured Initial Flaw Size Distribution
Authors: DeBartolo EA , Hillberry BM 
Published: May 2004

Abstract
Measured cracked particle distributions were used in conjunction with a closure-based life prediction package (FASTRAN 3.8 [1]) to predict fatigue life distributions under a spectrum load (FALSTAFF — Fighter Aircraft Loading STAndard For Fatigue [2]) in 2024-T3 aluminum. A single crack model was assumed and no threshold stress intensity factor was used. Simulations were done at maximum stress levels of 175, 205, and 275 MPa. The resulting fatigue life distributions were compared at different levels of probability of failure. At all levels, predicted fatigue lives were within a factor of two or better of experimental fatigue lives. This indicates both that the single-flaw model can be a reasonable approximation for life prediction and that it is not necessary to truncate initial flaw size distributions at some threshold level.
Investigation of the Behavior of Geosynthetic Clay Liners Subjected to Thermal Gradients in Basal Liner Applications
Authors: Southen JM , Rowe RK 
Published: May 2004

Abstract
Composite liners comprised of geomembranes and geosynthetic clay liners can be an effective means of minimizing fluid flow and associated groundwater contamination from municipal solid waste landfills. There remains uncertainty, however, regarding the long-term performance of such systems under conditions of elevated temperature that may occur at the base of landfills attributable to exothermic waste degradation processes. The heat generated by these processes may lead to the development of a thermal gradient through the lining system that creates a risk of desiccation within the uppermost portion of the subsoil and the geosynthetic clay liner itself. To investigate this issue, a series of small-scale laboratory experiments were developed in an effort to simulate the hydraulic and thermal conditions existing at the base of a landfill. This paper presents the results of investigations into the influence of various parameters on the behavior of a composite liner. The distribution of temperature and water content over time is discussed, as well as potential impacts on the performance of the geosynthetic clay liner.
Determining Residual Stress in Spherical Components: A New Application of the Hole-Drilling Method
Authors: Montay G , Cherouat A , Garnier C , Lu J 
Published: May 2004

Abstract
The semidestructive hole-drilling technique for measuring in-depth residual stress is well established for plane components. The strain-stress relationship requires calibration coefficients that can be determined either experimentally or numerically. Experimental determination of the calibration coefficient is very costly compared with numerical determination. Also, experimental determination cannot take into account the new stress distribution between two subsequent drillings. This is why the numerical solution was chosen to determine the calibration coefficients for spherical components in this study. We used the technique on a steering joint and compared the residual stress results obtained for a plane and a spherical structure. The error is discussed. This new development is also applicable on a hip prosthesis and other spherical shape components.
Testing and Comparison of Various Packages for Mango Distribution
Authors: Chonhenchob V , Singh SP 
Published: May 2004

Abstract
Various packages (corrugated box, plastic crate, and bamboo basket) used for mango distribution were evaluated for their protective performance. After subject to packaging and transportation, the quality of mangoes (bruise incidence, bruise volume, weight loss, firmness, color, ethylene production, and respiration rates) was determined. Different cushioning methods (foam net and paper wrap) were also evaluated for their effectiveness in protecting the fruits from mechanical damage during distribution. All types of cushioning materials tested reduced the amount of bruising. Corrugated box with foam net provided the best protection as compared to all other types of packaging tested. Mangoes packaged in bamboo baskets showed the highest mechanical damage and weight loss. Bruise volume during storage is highly correlated with bruise incidence after transportation and can be used to classify the market value of mangoes. Economic comparison of various packaging systems was also studied. The information from this study can be used for selecting proper packaging to reduce mechanical damage of mangoes and other sensitive tropical fruits during distribution.
Evaluation of the Uniaxiality of the Stress State in C-Ring Fracture Strength Specimens
Authors: Embree TL , Segall AE 
Published: May 2004

Abstract
To develop guidelines for using C-ring specimens for evaluating the fracture strength of ceramics in tubular form, a series of finite-element analysis (FEA) calculations was performed. These calculations focused on the ranges of specimen dimensions and loading distributions required to maintain a uniaxial stress state within the C-ring specimen under diametral loading. Results of the FEA calculations indicated that the degree of uniaxiality of the C-ring stress state could be described completely by a combination of the width-to-thickness ratio (b/t) and the inner radius-to-outer radius ratio (ri/ro). It was also found that a reasonably wide range of geometries can be used with accuracy to extract fracture strength design data, provided b/t does not get too large or ri/ro too low. Given the potential statistical distribution of flaws in most ceramics, there is also cause for concern when b/t → 0 or ri/ro → 1 as this implies a small sample of flaws in the critical tensile stress region. Calculations also indicated that the uniaxiality of the C-ring stress state followed the expected 1/v dependence so that the behaviors of different materials can be surmised easily from the current results calculated for v = 0.155. As expected, and in contrast to O-ring specimens, the loading distribution between the C-ring surface and platum do not seem to have any effect on the stress state.
Chemometric Studies in the Lagoon of Venice, Italy. Annual Evolution of Sulphur Species and Relationship to Biogeochemical Cycles in Lagoon Water
Authors: Moret Ivo , Gambaro Andrea , Piazza Rossano , Corami Fabiana , Ravazzi Cesare , Andreoli Carlo , Truzzi Cristina , Lambertucci Luca , Scarponi Giuseppe 
Published: May 2004

AbstractDuring the period March 1997 — March 1998 dimethyl sulphide (DMS), dimethylsulphoniopropionate (DMSP) and carbon disulphide (CS2) were determined weekly in the water of the Lagoon of Venice, Italy (at three stations located in the Giudecca Canal, the San Secondo Canal and the Rio di San Nicolò). At the same time, the following hydrological and biological variables were also measured: tide height, temperature, transmittance, fluorescence, pH, salinity, chlorinity, sulphate, ammonia, nitrite, nitrate, phosphate, silicate, chlorophyll a, phaeopigments, phytoplankton (abundance and biomass). Principal component analysis (PCA), applied as a dimension reduction tool, made it possible to summarize multivariate information in a small number of components, which highlighted the relationships between the temporal evolutions of the sulphur compounds with hydrological and biological variables in the seasonal biogeochemical cycle of the lagoon. In particular the overall temporal cycle, which begins with the development of biological activity in late winter and spring, followed by the predominance of degradation processes during the late summer and the remineralization of nutrients in autumn, is clearly described in the plane of the first two principal components, together with the interrelationships between all the relevant variables.
Photocatalytic Mineralisation of Aniline Derivatives in Aquatic Systems Using Semiconductor Oxides
Authors: Habibi Mohammad Hossein , Khaledisardashti Mohammad , Montazerozohori Morteza 
Published: May 2004

AbstractPhotocatalytic degradation of aqueous solution of aniline derivatives such as ortho‐nitroaniline(ONA), meta‐nitroaniline(MNA), para‐nitroaniline(PNA), 4‐ bromoaniline(4‐BrA) and 2‐chloroaniline(2‐ClA) were carried out over ZnO or TiO2 (anatase and rutile) in a photocatalytic reactor. The observed results revealed that the order of photocatalytic activity for degradation of selected compound was ZnO > TiO2 (rutile) > TiO2 (anatase) with the ratio of the rate constants to the surface area of 3.2 × 10‐3, 1.9 × 10‐3 and 1.0 × 10‐3 respectively. The effect of some physical and chemical parameters such as amount of photocatalyst, pH, time of irradiation and solvent were studied. Degradation kinetic was according to Longmuir behaviour. Spectrophotometric methods and TOC analysis supported that aniline derivatives almost completely mineralized.
Differential Pulse Polarographic Determination of Lead in Standard Alloys and Biological Samples after Separation and Preconcentration with PAN
Authors: Taher Mohammad Ali 
Published: May 2004

AbstractA highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amount of lead in various samples after adsorption of its 1‐(2‐pyridylazo)‐2‐naphthol (PAN) on naphthalene in the pH range of 8.4 — 11.5. After filtration, the solid mass is shaken with 9.0 ml of 1 M hydrochloric acid and lead is determined by differential pulse polarography (DPP). Lead can alternatively be quantitatively adsorbed on [1‐(2‐pyridylazo)‐2‐naphthol]‐naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.1 μg/m1 (signal to noise ratio = 2) and the linearity is maintained in the concentration range 0.3 — 300 μg/m1 with a correlation coefficient of 0.9996 and relative standard deviation of ±1.1%. Characterization of the electroactive process included an examination of the degree of reversibility. Various parameters such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of lead has been studied in detail to optimize the conditions for determination in alloys and biological samples.
Octadecyl Silica Membrane Disks Modified with a New Schiff's Base for the Preconcentration of Lead and Copper before Their Determination in Water Samples
Authors: Ganjali Mohammad Reza , Pourjavid Mohammad Reza , Hajiagha Babaei Leila , Salavati‐Niasari Masoud 
Published: May 2004

AbstractA simple and fast method for the extraction and determination of ppt level of Pb2+ and Cu2+ ions using octadecyl‐bonded silica membrane disks modified by a new tetradentates Schiff's base [Bis(2, 4‐dimethoxy benzaldehyde) ethylen diimine](TDSB) and inductively coupled plasma atomic emission spectrometry is described. Extraction efficiency, and influence of flow rate, pH, type and the least amount of acid for stripping of Cu2+ and Pb2+ from the modified disks and break through volume were evaluated. The maximum capacity of the membrane disks modified by 5 mg of TDSB used was found to be 347±7 and 470±6 μg of copper and lead, respectively. The concentration factor is 500 (for 2500 mL water sample and flow rate of 20 mL min‐1) and detection limit of the proposed method is 12.5 and 150.5 pg/ml for Cu2+and Pb2+, respectively. The method was applied to the determination of Cu2+ and Pb2+ ions from various water, wastewater, black tea, and hot pepper samples.
Bindungsverhalten ausgewählter Elemente in Sedimenten eines sauren Tagebaurestsees/FNR>
Authors: Einax Jürgen W. , v. Tümpling Wolf , Zehl Katharina 
Published: May 2004

AbstractZur wirtschaftlichen Nutzung saurer Tagebaurestseen sind zur Erarbeitung von Sanierungskonzepten und zu deren Anwendung detaillierte Kenntnisse hinsichtlich Wasserkörper und Sediment notwendig. Die vorliegende Arbeit hat das Bindungsverhalten und die vertikale Verteilung von ausgewählten Elementen (Aluminium, Blei, Cobalt, Eisen, Kupfer, Mangan, Nickel, Zink) im Sediment des sauren Tagebaurestsees 111 (Niederlausitz) zum Gegenstand. Ziel der Untersuchungen war eine Schätzung des vom Sediment ausgehenden Gefährdungspotentials durch die ausgewählten Metalle.
Treatment of Malting Wastewater in a Granular Sludge Sequencing Batch Reactor (SBR)
Authors: Schwarzenbeck Norbert , Erley Ron , Mc Swain Belinda S. , Wilderer Peter A. , Irvine Robert L. 
Published: May 2004

AbstractAerobic granular sludge was successfully cultivated in a sequencing batch reactor (SBR) treating wastewater from the malting process with a high content of particulate organic matter. At an organic loading rate of 3.2 kg/(m3 d) CODtotal and an influent particle concentration of 0.95 g/L MLSS an average removal of 50% in CODtotal and 80% in CODdissolved could be achieved. A comparison of granular and flocculent sludge grown under the same operating conditions showed no significant difference in removal efficiency although granules exhibited a higher metabolic activity in terms of specific oxygen uptake rate (rO2, X). Two distinct mechanisms of particle removal were observed for granular sludge: during initial granule formation, particles were incorporated into the biofilm matrix. For mature granules, a high level of protozoa growth on the granule surface accounted for the ability to remove particulate COD. Combined evaluation of the development in MLSS content and sludge bed settling rate (i.e., mean derivative of the normalized sludge volume) was found to be an adequate method for monitoring the characteristic settling properties of a granulizing sludge bed. By means of this method, a distinct substrate gradient out of several operating conditions was concluded to have the biggest impact on the formation of aerobic granular sludge.
Membrane Ozonation in Wastewater Treatment
Authors: Janknecht Peter , Picard Céline , Larbot André , Wilderer Peter A. 
Published: May 2004

AbstractThe utilization of porous membranes in mass transfer processes of gaseous ozone to water was investigated. With this approach a direct control of the interface between gas and liquid is possible. Furthermore it prevents foam formation in the presence of surfactant pollution, which constitutes a problem in conventional ozonation methods. Different organic and inorganic membrane materials and geometrical arrangements were utilized and ozone transfer under varied experimental conditions was determined. Typical transfer rates obtained in the experiments were 10 g ozone per membrane square meter and hour, but under optimized conditions higher values were possible. A theoretical model was successfully applied to the results obtained. A peculiarity of the method is its inherent ozone dose control in relation to the volume flow of water.
The influence of time after stroke on brain activations during a motor task
Authors: Ward Nick S. , Brown Martin M. , Thompson Alan J. , Frackowiak Richard S. J. 
Published: May 2004

AbstractAfter stroke, the pattern of brain activation during performance of a motor task is related to outcome. Here, we compare this relationship in the early (10–14 days) and late (at least 3 months) phases after first‐ever stroke. A negative linear relationship between task‐related brain activation, as measured by functional magnetic resonance imaging, and outcome is seen in several identical primary and nonprimary motor regions that is independent of time after stroke. In other words, patients with poorer outcome scores recruit more widely within motor‐related regions in both the early or late poststroke phase. However, in contralesional middle intraparietal sulcus, contralesional cerebellum, and ipsilesional rostral premotor cortex, this relationship is seen only in the early poststroke phase. Thus, patients with poorer outcome scores recruit these areas in only the early and not the late poststroke phase. These results suggest that there are differences in the cerebral implementation of action in patients with poor outcome that are dependent on the time since stroke. Thus, in those patients with the most to gain from rehabilitation, different therapeutic approaches may be required at different stages after stroke.
Functional brain changes in presymptomatic Huntington's disease
Authors: Reading Sarah A. J. , Dziorny Adam C. , Peroutka Laura A. , Schreiber Mathew , Gourley Lisa M. , Yallapragada Venu , Rosenblatt Adam , Margolis Russell L. , Pekar James J. , Pearlson Godfrey D. , Aylward Elizabeth , Brandt Jason , Bassett Susan S. , Ross Christopher A. 
Published: May 2004

AbstractEvidence suggests early structural brain changes in individuals with the Huntington's disease (HD) genetic mutation who are presymptomatic for the movement symptoms of the illness. The aim of this study was to investigate the presence of functional brain changes in this same population using functional magnetic resonance imaging. Subjects and matched controls underwent an functional magnetic resonance imaging “interference” protocol, a task known to be mediated in part by corticostriatal circuitry. In the setting of normal cognitive performance, presymptomatic HD subjects had significantly and specifically less activation in the left anterior cingulate cortex (BA 24, 32) compared with matched controls. Ann Neurol 2004;55:879–883
The 14q restless legs syndrome locus in the French Canadian population
Authors: Levchenko Anastasia , Montplaisir Jacques‐Yves , Dubé Marie‐Pierre , Riviere Jean‐Baptiste , St‐Onge Judith , Turecki Gustavo , Xiong Lan , Thibodeau Pascale , Desautels Alex , Verlaan Dominique J. , Rouleau Guy A. 
Published: May 2004

AbstractA new restless legs syndrome locus on chromosome 14 recently has been reported in one family of Italian origin. Our study aimed to replicate this finding and determine the importance of this locus in the French Canadian population. Markers spanning the region were genotyped in 14 large families and linkage assessed using two‐point and multipoint logarithm of odds scores. Possible linkage to this locus was found in one of our kindreds providing support for the existence of this locus and indicating that this locus may be responsible for a small fraction of French Canadian restless legs syndrome. Ann Neurol 2004;55:887–891
RNAinterferenz: Gen, sei still!
Authors: Kuhlmann Markus , Nellen Wolfgang 
Published: May 2004

Abstract„RNA Interferenz”︁ steht seit 1998 für einen völlig neuen Mechanismus des „Gene Silencing”︁, in dem mRNAs über einen komplexen Mechanismus mit Hilfe doppelsträngiger RNA degradiert werden. Das schnell wachsende Verständnis für diese molekulare Maschinerie hat zusätzlich zu überraschenden Erkenntnissen über Virusabwehr, Chromatinorganisation und eine Klasse neuer Regulatoren, den miRNAs, geführt. RNAi ist zu einem unverzichtbaren Werkzeug der Grundlagenforschung geworden. Medizinische Applikationen werden vorbereitet.