bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Real-Time Traffic Control in Metro Stations
Authors: Mannino Carlo , Mascis Alessandro
Published: March 2009

Train movements across railway stations are still operated by human dispatchers. Motivated by an application provided by Azienda Trasporti Milanesi (ATM), the major Italian municipal transport company, we developed a real-time automated traffic control system to operate trains in metro stations. The system optimally controls the trains in a metro station by identifying a suitable routing and by establishing an optimum schedule of the performed operations. For each candidate routing an instance of the blocking, no-wait job-shop scheduling problem with convex costs is solved to optimality by branch and bound. A new, effective lower bound is developed to speed up the enumeration process. Computational testing in a real environment proved that the algorithm is able to solve relevant practical instances within the very tight time limit imposed by the application. The system has been in operation in the Milan metro since July 2007. To our knowledge, this is the first example of successful application of optimization methods to real-time traffic control in metro stations.
Pro-Inflammatory Cytokines TNF-Related Weak Inducer of Apoptosis (TWEAK) and TNFα Induce the Mitogen-Activated Protein Kinase (MAPK)-Dependent Expression of Sclerostin in Human Osteoblasts
Authors: Vincent Cristina , Findlay David M , Welldon Katie J , Wijenayaka Asiri R , Zheng Timothy S , Haynes David R , Fazzalari Nicola L , Evdokiou Andreas , Atkins Gerald J
Published: March 2009

We have recently shown that TNF-related weak inducer of apoptosis (TWEAK) is a mediator of inflammatory bone remodeling. The aim of this study was to investigate the role of TWEAK in modulating human osteoblast activity, and how TWEAK and TNFα might interact in this context. Recombinant TWEAK and TNF were both mitogenic for human primary osteoblasts (NHBC). TWEAK dose- and time-dependently regulated the expression of the osteoblast transcription factors RUNX2 and osterix. TWEAK inhibited in vitro mineralization and downregulated the expression of osteogenesis-associated genes. Significantly, TWEAK and TWEAK/TNF induced the expression of the osteoblast differentiation inhibitor and SOST gene product, sclerostin. Sclerostin induction was mitogen-activated protein kinase (MAPK) dependent. The SOST mRNA levels induced by TWEAK were equivalent to or exceeded those seen in steady-state human bone, and the TWEAK/TNF induction of SOST mRNA was recapitulated in fresh cancellous bone explants. TWEAK-induced sclerostin expression was observed in immature osteoblastic cells, both in cycling (Ki67+) primary NHBC and in the cell lines MC3T3-E1 and MG-63, as well as in human osteocyte-like cells and in the osteocyte cell line, MLO-Y4. Treatment of NHBC with recombinant human sclerostin mimicked the effects of TWEAK to suppress RUNX2 and osteocalcin (OCN). TWEAK, TNF, and sclerostin treatment of NHBC similarly altered levels of phosphorylated and total GSK3β and active and total levels of β-catenin, implying that the Wnt signaling pathway was affected by all three stimuli. Sclerostin also rapidly activated ERK-1/2 MAPK signaling, indicating the involvement of additional signaling pathways. Together, our findings suggest that TWEAK, alone and with TNF, can regulate osteoblast function, at least in part by inducing sclerostin expression. Our results also suggest new roles and modes of action for sclerostin.
Tribute to Professor Michael Gibbins
Authors: Jamal Karim
Published: March 2009

On May 2‐3, 2008, the Alberta School of Business and the Institute of Chartered Accountants of Alberta (ICAA) sponsored a dinner and a one‐day research workshop in Professor Michael Gibbins's honor. At the dinner on May 2, three presentations were made on the contribution of Professor Gibbins to accounting education, research, and the profession. At the research workshop on May 3, three research papers were presented, a panel discussed professional judgment issues in accounting and auditing, and a CFO gave a luncheon speech on the new financial presentation project of the Financial Accounting Standards Board. The dinner and symposium attracted participants from across Canada, the United States, Australia, and Singapore, which is not surprising given Professor Gibbins's global reputation. This paper summarizes the presentations and discussion that took place during the May 2 dinner and May 3 research workshop.
Brücken-Glossar (DE–EN) (2. Teil)
Authors: Wuttke Susanne
Published: March 2009

Brücken scheinen neuerdings auch von der Öffentlichkeit bewusster wahrgenommen zu werden, jedenfalls fällt auf, dass sich gerade in jüngster Zeit in den Printmedien und im Fernsehen Beiträge mit dem Brückenbau befasst haben. Das folgende Glossar stammt aus dem dritten Hauptteil der Diplomarbeit „Brücken. Eine terminologische Untersuchung im Deutschen und Englischen“, die am 18.09.2003 am Institut für Angewandte Linguistik und Translatologie (IALT) der Universität Leipzig eingereicht wurde. Das mit CATS erstellte Glossar enthält 1374 Datensätze mit 467 Begriffen, 937 dt. und 904 engl. Benennungen sowie deutschen und englischen Definitionen nahezu aller Begriffe; im Folgenden drucken wir die Richtung deutsch-englisch.
L'héritage de Brigitte Sauzay (1947–2003)
Authors: Seren-Rosso M. L.
Published: March 2009

Ancienne grande interprète des présidents français, devenue en 1998 conseillère de Gerhard Schröder pour les relations franco-allemandes, Brigitte Sauzay a mis pendant cinq ans sa connaissance fine de l'Allemagne au service de nouvelles synergies entre Berlin et Paris. Cet apport décisif au rapprochement des deux pays, elle le devait aussi, selon ses propres termes, aux acquis de son premier métier. En nous quittant, elle laisse un modèle qui préfigure, par sa conviction et son courage, l'évolution de nos professions vers des profils novateurs.
Glossar Flughafentechnik und -betrieb (DE–EN) (2. Teil)
Authors: Künstner Bianca
Published: March 2009

Ein Jahrhundert nach den ersten Flugversuchen der Gebrüder Wright und anderer Flugpioniere reicht eine ebene Wiesenfläche für Start und Landung der Fluggeräte schon lange nicht mehr aus. So rasant, wie sich die Technik der Flugzeuge entwickelte, mussten auch die Flughäfen Schritt halten. Die heutigen komplexen Gebilde mit ihren ausgeklügelten Organisationsabläufen und raffinierten Technologien wecken immer noch Faszination bei den meisten Menschen, obwohl die Reise mit dem Flugzeug mittlerweile zum Alltag zählt und mit fortschreitender Globalisierung auch immer mehr an Bedeutung gewinnt. Ein Ziel der am Institut für Angewandte Linguistik und Translatologie (IALT) der Universität Leipzig eingereichten Diplomarbeit „Verkehrsflughäfen. Eine terminologische Untersuchung im Deutschen und Englischen“ war es, einen Einblick in die häufig im Verborgenen liegenden Abläufe und Technologien auf einem Verkehrsflughafen zu geben. Einen Hauptteil der Diplomarbeit bildete auch das im Folgenden in der Sprachrichtung Deutsch-Englisch abgedruckte Glossar. Es wurde mit dem Terminologieverwaltungsprogramm CATS erstellt und enthält 1549 Datensätze mit 502 Begriffen, zu denen es 984 deutsche und 1067 englische Benennungen sowie 497 deutsche Definitionen gibt.
Glossar Flughafentechnik und -betrieb (DE–EN) (1. Teil)
Authors: Künstner Bianca
Published: March 2009

Ein Jahrhundert nach den ersten Flugversuchen der Gebrüder Wright und anderer Flugpioniere reicht eine ebene Wiesenfläche für Start und Landung der Fluggeräte schon lange nicht mehr aus. So rasant, wie sich die Technik der Flugzeuge entwickelte, mussten auch die Flughäfen Schritt halten. Die heutigen komplexen Gebilde mit ihren ausgeklügelten Organisationsabläufen und raffinierten Technologien wecken immer noch Faszination bei den meisten Menschen, obwohl die Reise mit dem Flugzeug mittlerweile zum Alltag zählt und mit fortschreitender Globalisierung auch immer mehr an Bedeutung gewinnt. Ein Ziel der am Institut für Angewandte Linguistik und Translatologie (IALT) der Universität Leipzig eingereichten Diplomarbeit „Verkehrsflughäfen. Eine terminologische Untersuchung im Deutschen und Englischen“ war es, einen Einblick in die häufig im Verborgenen liegenden Abläufe und Technologien auf einem Verkehrsflughafen zu geben. Einen Hauptteil der Diplomarbeit bildete auch das im Folgenden in der Sprachrichtung Deutsch-Englisch abgedruckte Glossar. Es wurde mit dem Terminologieverwaltungsprogramm CATS erstellt und enthält 1549 Datensätze mit 502 Begriffen, zu denen es 984 deutsche und 1067 englische Benennungen sowie 497 deutsche Definitionen gibt.
Dolmetschen für den öffentlichen Bereich in der Schweiz
Authors: Hofer Gertrud
Published: March 2009

Im Laufe des 20. Jahrhunderts hat aufgrund der Migration die Viersprachigkeit in der Schweiz der Vielsprachigkeit Platz gemacht. Die Sprachpalette hat sich laufend verändert und vergrössert. Damit ist auch der Bedarf an Dolmetschleistungen um ein Vielfaches gestiegen. In erster Linie sind Behörden, Gerichte, Krankenhäuser, psychiatrische Kliniken und Schulen auf Dolmetschende angewiesen. Ein grosser Anteil dieser Verdolmetschungen betrifft Sprachen, für die es keine anerkannte Dolmetschausbildung gibt.

Migrant/innen dolmetschen zwar in den verschiedenen Institutionen, sind sich aber ihrer Rolle als Dolmetschende häufig nicht bewusst und kennen die Dolmetsch- und Notizentechniken nicht. Überdies haben sie oft ungenügende Kompetenzen in einer der Sprachen und beherrschen die Syntax und/oder die Terminologie nicht im erforderlichen Mass, und zudem haben viele keinen Zugang zu den komplexen fachlichen Inhalten der verschiedenen Bereiche im Rechts-, Gesundheits- oder Bildungswesen. Aus diesen Gründen ist die Qualität der Dolmetschleistungen oft mangelhaft, weshalb es zu Beanstandungen oder zum Abbruch von Gesprächen und Verhandlungen kommt.

Diese Migrationsflüsse der Gegenwart führen in der Schweiz wie auch in zahlreichen anderen Ländern zu Kommunikationsproblemen, zu deren Lösung die Institute für Übersetzen und Dolmetschen einen wesentlichen Beitrag leisten können. So besteht seit wenigen Jahren im Kanton Zürich ein dreistufiges Programm für Behördenund Gerichtsdolmetscher/innen.
Bagger-Glossar (DE–EN/EN–DE)
Authors: Ischganeit Thomas
Published: March 2009

Am 09 Juli 2003 wurde der feierliche Baubeginn für den Leipziger Citytunnel begangen und seit diesem Tag kann niemand mehr durch Leipzig gehen, ohne sich der vielen Baustellen und der sich darauf befindenden Hoch- und Tiefbautechnik bewusst zu werden. Auf jeder dieser Baustellen findet man Bagger in allen Formen, Farben und Größen. Man sieht die kleinen, sehr leistungsfähigen Minibagger, mittelgroße, beinahe alltäglich gewordene Bagger und die großen Ungetüme, die nach wie vor für ungläubiges Staunen sorgen. Diese am Institut für Angewandte Linguistik und Translatologie (IALT) der Universität Leipzig eingereichte Diplomarbeit „Bagger. Eine terminologische Untersuchung im Deutschen und Englischen“ verfolgte die Zielsetzung, einen Einblick in die vielen verschiedenen Baggertypen, einschließlich der unterschiedlichen Technologien, zu geben. Einen Hauptteil der Diplomarbeit bildete auch das im Folgenden in den Sprachrichtungen Deutsch-Englisch und Englisch-Deutsch abgedruckte Glossar. Es wurde mit dem Terminologieverwaltungsprogramm CATS erstellt und enthält 453 Datensätze mit 205 Begriffen, zu denen es 299 deutsche und 359 englische Benennungen gibt.
Glossar Photovoltaik (DE–ES) (2. Teil)
Authors: Streit Silke
Published: March 2009

Auch in der Photovoltaikbranche haben sich in den letzten zehn Jahren tief greifende Entwicklungen vollzogen. Durch die Vorreiterrolle Deutschlands im Bereich Photovoltaik (PV) nehmen auch internationale Forschungs- und Handelsbeziehungen sowie die Zusammenarbeit mit Unternehmen im Ausland stetig zu. So bestehen auch enge Geschäftsbeziehungen zwischen Deutschland und Spanien: Deutsche Solarzellenhersteller beliefern spanische Modulhersteller, spanische Unternehmen bauen deutsche PV-Anlagen unter spanischer Sonne auf und folglich wächst der Bedarf an deutsch/spanischer Kommunikation – und Übersetzungen – auf diesem Fachgebiet. Eine Quelle von Problemen sind dabei die auffallend zahlreichen Synonyme – wobei das Problem (nicht nur für Übersetzer) eben darin besteht, Synonyme überhaupt als solche zu erkennen. Das folgende Glossar schafft Klarheit: Es stammt aus der Diplomarbeit „Photovoltaik. Eine terminologische Untersuchung im Deutschen und Spanischen“, die am 07.02.2007 am Institut für Angewandte Linguistik und Translatologie (IALT) der Universität Leipzig eingereicht und mithilfe von CATS erstellt wurde. Es enthält 500 Begriffe, davon 307 mit Definitionen, mit 983 deutschen und 858 spanischen Benennungen. Die gesamte Diplomarbeit wird demnächst im Rahmen einer neuen Schriftenreihe des IALT veröffentlicht.
Method of Compaction has Significant Effects on Stress-Strain Behavior of Hydraulic Asphalt Concrete
Authors: Wang Weibiao , Höeg Kaare
Published: March 2009

Four different laboratory compaction methods, i.e., the Marshall, vibration, static, and gyratory methods, were used to study the effects of type of compaction method on the triaxial stress-strain behavior of asphalt concrete. The behavior was compared to that of asphalt concrete compacted in the field by a vibratory roller. Although the asphalt concrete specimens were all made of the same mix and compacted to approximately the same density (air voids), the resulting stress-strain curves were very different. The secant modulus up to 1 % axial strain for the gyratory compacted specimens was six times that of the field compacted specimen, and the axial strain of the field specimen at failure was six times that of the gyratory specimen. The reason is that, although the asphalt concrete density is the same for the different specimens, the aggregate particle arrangement and interlocking (skeleton structure) after compaction are very dependent upon the method of compaction used. For field quality control, common practice is to compare the behavior of field compacted specimens to specifications based on laboratory specimens. Therefore, it is important to use laboratory compaction methods that yield specimens with behavior similar to that resulting from roller compaction in the field. Two such methods are proposed, a modified Marshall method and a special compaction method.
Effects of Cycles below the Fatigue Limit on the Life of a High Strength Steel
Authors: Teimourimanesh Shahab , Nilsson Fred
Published: March 2009

The objective of this work was to study the hypothesis of the possible influence of stress ranges below the fatigue limit on the fatigue life of the material. The experiments were conducted on high strength steel (Uddeholm Impax Supreme®, a CrNiMo steel) with tension-tension periodic blocks under stress control. The fatigue limit of the steel for tension-tension was determined by the staircase method. The programmed loading contained one repeated sequence of two ranges of stress cycles, above and below the fatigue limit. One-sided t-testing showed that it cannot be concluded that there is a significant influence of the range of stress below the fatigue limit on the fatigue life of the material, although a slight beneficial effect was indicated.
Comparing the Effect of Inclusions on Ductility, Toughness, and Fatigue Properties
Authors: Wilson AD
Published: March 2009

The nonmetallic inclusion structure in a steel has been demonstrated to have a dramatic effect on mechanical properties and lamellar-tearing resistance. Although the through-thickness tension test has become widely used to assure a level of quality with regard to both of these items, the toughness and fatigue properties are also of concern. This study compares the tensile, Charpy V-notch impact, and fatigue crack propagation properties in the three major testing orientations of six plate steel grades in each of two quality levels (inclusion structures). The primary emphasis of the study was to establish which parameters from these test methods were most sensitive to inclusion structure. Generally, the Charpy V-notch upper shelf energy was found to be the most sensitive parameter to changes in inclusion structure. In steels with higher inclusion levels, however, the through-thickness tensile reduction of area was most sensitive. This appeared to take place when this value was less than 25 percent. Correlations among the various testing parameters were also identified.
Drop-Weight Testing of Nonstandard Geometries
Authors: Low SR , Early JG
Published: March 2009

The test requirements contained in the standard test method for drop-weight testing, the ASTM Method for Conducting Drop-Weight Test to Determine Nil-Ductility Transition Temperature of Ferritic Steels (E 208-81), generally limit its applicability to flat products or to products with at least one flat surface; this is done because of the shape of the standard test specimens and the need for the tension surface of the specimen to be an as-fabricated surface. Difficulties arise in the application of ASTM Method E 208-81 to steel products whose fabricated shapes are not flat, for example, piping and pressure vessels. For products with curved surfaces, some of the testing requirements must be violated; these include keeping the as-fabricated surface as the tension surface, uniform specimen thickness, a flat compression surface, and uniform stress on the tension surface. In this study, the nil-ductility transition (NDT) temperature was determined as a function of test specimen geometry for two carbon/manganese structural steel grades. The specimens were extracted from the head plates of railroad tank cars and were curved in two orthogonal directions. The sensitivity of the test results to variations in test specimen geometry has been determined as is reported here.
Development of Theoretical Models for Nondestructive Testing Eddy-Current Phenomena
Authors: Lord W , Palanisamy R
Published: March 2009

Eddy-current methods of nondestructive testing rely for their operation on the interaction of induced alternating currents and fields with defects to produce noticeable changes in search coil impedance. To date, analytical techniques have been largely ineffective in providing a model suitable for the basis of a general defect characterization scheme because of the inherent complexity of the field equations describing the phenomena. After an overview of the available analytical models, this paper describes the development of a numerical model that shows promise of providing a solution to the inverse eddy-current problem. Impedance plane trajectories are predicted for a differential probe passing through a tube with axisymmetric inside-diameter and outside-diameter slots to illustrate the use of the numerical approach.
Eddy-Current Simulation in Prisms, Plates, and Shells with the Program EDDYNET
Authors: Turner LR , Lari RJ , Sandy GL
Published: March 2009

The program EDDYNET solves eddy-current problems by means of an integral-equation approach. The conducting material is represented by a network of current-carrying line elements. Consequently, Maxwell's field equations can be replaced by Kirchhoff's circuit rules.

The loop equations for voltages, supplemented by the node equations for the currents, comprise a set of linear equations that can be solved repeatedly to give the time development of the eddy currents. Currents, magnetic fields, and power are calculated at each step.

A TRIM-like mesh generator and internal indexing of lines, nodes, and loops permit solutions with complex geometries incorporating many elements. Results can appear in the form of movies representing currents, field penetration, and power distribution.

Calculations can now be performed for conducting, curved shells acted upon by an applied magnetic field. Changes in the flux through each mesh loop are determined from the normal component of field (both the applied field and the field from the current in each line element). The matrix representing the flux through each loop due to each line can be inverted and the system stepped through time to provide a time history of the currents. Another matrix facilitates calculating the net field over a specified rectangular grid at each time step. Incorporating appropriate symmetry conditions reduces the size of the problem.

Results are presented for field shielding by a thin-walled toroidal shell and for eddy-current effects on a notched tube in a sinusoidal field.
High Peak Energy Shaped-Pulse Electromagnetic Crack Detection
Authors: Hendrickson IG , Hansen KA
Published: March 2009

A low-inductance drive coil energized with a shaped high-current drive pulse, together with a separate pickup coil, is used for crack detection in thick multiple-layer aircraft structures. The slow rise time or low-frequency portion of the shaped pulse applied to a solenoid drive coil is used to obtain the required depth-of-field penetration into the structure. The fast fall time or high-frequency portion of the shaped pulse is used to rapidly cancel the slow pulse current and field at the structure surface. This cancellation process causes the collapse of the field within the structure, which reacts with the structure and cracks. The structure/crack eddy-current response is detected at the structure surface with a spiral pancake pickup coil. The pancake pickup coil is used to selectively detect the tangential component of the drive pulse field collapsing from within the structure. An important aspect of this high peak energy testing approach is its saturation of steel fasteners, which highly reduces their permeability variations.
In-Service Evaluation of Multifrequency/Multiparameter Eddy-Current Technology for the Inspection of PWR Steam-Generator Tubing
Authors: Brown SD
Published: March 2009

The recent introduction of field-usable multifrequency/multiparameter instrumentation has provided a basis for the development of a near-term system for the inspection of pressurized water-reactor steam-generator tubing. Multifrequency eddy-currents offer benefits in the performance of parallel tests and a readily available data base for the identification of nonunique signals. Multiparameter methods allow for the minimization of extraneous test variables, that is, support plates and small dents, for the more reliable detection and characterization of tube degradation. The suppression of the extraneous variable in real time offers advantages over off-line computer/digital subtraction approaches. Experience with the system based on the in-service inspection of three steam generators is considered.
Pulsed Eddy-Current Testing of Steel Sheets
Authors: Waidelich DL
Published: March 2009

This is a brief report on some early work on the testing of steel sheets using pulsed eddy currents. Penetration up to about 10 mm has been achieved and some artificial defects have been observed. Longer pulses are to be employed for deeper penetration, and more work done on the observation of defects. Some theoretical work is also reported. An indication is given of further work and the preparation of computer programs to produce a calculated output pulse where the input pulse shape is known.
Pattern-Recognition Methods for Classifying and Sizing Flaws Using Eddy-Current Data
Authors: Doctor PG , Harrington TP , Davis TJ , Morris CJ , Fraley DW
Published: March 2009

This paper extends the work of Shankar et al to the classification of three types of machined defects in Inconel 600 steam-generator tubing: electrodischarge machined slots, uniform thinning, and elliptical wastage. Three different pattern-recognition techniques were used for classification: (1) an empirical Bayes procedure, (2) a nearest-neighbor algorithm, and (3) a multicategory linear discriminate function. The three types of defects were classified correctly with an overall accuracy of 96 to 98 percent depending on the technique used. Two pattern-recognition algorithms, least squares and nearest neighbor, were used to size uniform-thinning defects in steam-generator tubing. All of the defects were between 25 and 75 percent of the wall in depth. With the least-squares algorithm, we achieved a fit correlation of 0.99 with a 95 percent confidence interval of (0.98, 1.00).
Automatic Detection, Classification, and Sizing of Steam-Generator Tubing Defects by Digital Signal Processing
Authors: Brown CL , Defibaugh DC , Morgan EB , Mucciardi AN
Published: March 2009

An eddy-current analysis system is being developed for the inspection of steam-generator tubing that provides automatic interpretation of eddy-current signals. The microprocessor-based system realizes real-time analysis capability through a programmed probe controller, on-line data conversion, and high-speed digital signal processing. In a fully automatic mode, a wide variety of anomalies can be detected by appropriate enhancement of their characteristic wave shapes. Each detected signal is transformed and parameterized to yield a set of representative features that are used to classify the type of anomaly. An additional feature set is then extracted for estimating the depth of the discontinuity. Classification and sizing capabilities are provided by adaptive learning networks that were trained on a data base of simulated-defect waveforms. Machined defects were utilized in training to simulate as much as possible the most prevalent problems of stress-corrosion cracking, pitting, wastage (wall thinning), and denting of steam-generator tubing. The data base includes combinations of these defect types as well. The range of depth estimation is from 10 to 100 percent of the tube-wall thickness. The system has been designed to interface with either single-frequency or multifrequency devices.
Fatigue Properties of Unnotched, Notched, and Jointed Specimens of a Graphite/Epoxy Composite
Authors: Schütz D , Gerharz JJ , Alschweig E
Published: March 2009

Within a continuing program on high tensile graphite/epoxy composite, stress-strain, axial fatigue, and compliance behavior of unnotched, notched (3-mm diameter hole), and jointed specimens made of [O2/±45/O2/±45/90]s T300/914C laminates (177°C curing temperature) have been studied. In addition, the behavior of unnotched specimens cut from (1) the same laminate but with the longitudinal specimen axis now perpendicular to the zero-degree fiber direction, and (2) the high modulus fiber laminate with the same build-up was investigated.

Stress-strain curves, S-N curves, and increase-in-compliance versus percentage-of-total life curves were determined for all specimen types for stress ratios, R, ranging from R = +5.0 (compression-compression cycling, C-C) to R = +0.1 (tension-tension cycling, T-T).

An overall comparison of results from specimens with different stress raisers shows that the stress raisers diminish fatigue strength in the low-cycle range, but in the high-cycle range their influence has vanished. Effective stress concentrations were found to be different for compression and tension. During T-C cycling, increase of compliance was lowest for the fastener-filled no-load transfer joint and largest for the single-shear load transfer joint. The large compliance changes of the load-transfer specimens were attributed to increased bearing damage.

In general, the scatter in static and fatigue strength was found to be comparable with that for similar features in metals. When the plain material was loaded transversely instead of longitudinally, static and fatigue strength were lower by a factor of about 3.
Effects of Proof Test on the Strength and Fatigue Life of a Unidirectional Composite
Authors: Wang ASD , Chou PC , Alper J
Published: March 2009

The effects of a static proof testing on the statistical distribution of the static strength and fatigue life of a unidirectional graphite-epoxy laminate (AS-3501-05) are investigated experimentally. Loading mode for both the static and fatigue tests is restricted to uniaxial tension in the fiber direction. Six-ply tension coupons with dimensions of 22.9 cm by 1.9 cm are used; and all tests are conducted using a closed-loop Instron tester, under room temperature (∼21°C) and ambient humidity (∼60% percent relative humidity) conditions. Test data are analyzed by means of a two-parameter Weibull distribution in conjunction with the maximum likelihood method for parameter estimation. Results show that proof testing can guarantee a minimum static strength, and to a lesser degree, the method can also assure a minimum fatigue life.
Fatigue Characterization of Composite Materials
Authors: Whitney JM
Published: March 2009

A procedure is outlined that allows the generation of an S-N curve with some statistical value without resorting to an extremely large data base. The procedure is based on a power law representation of the S-N curve and a two-parameter Weibull distribution for time-to-failure at a specific stress level. A data pooling scheme is also discussed that allows the determination of a fatigue shape parameter that is independent of stress level.
Evaluation of the Effects of Effluents on Aquatic Life in Receiving Waters—An Overview
Authors: Weber CI
Published: March 2009

Federal water pollution control legislation strongly emphasizes the need to protect aquatic life from adverse effects of effluents. Effluent biomonitoring, therefore, plays an important role in the federal water pollution control program, and includes two basic functions: (1) measurement of the toxicity and biostimulatory properties of effluents, and (2) measurement of the effects of effluents on the biological integrity of receiving waters, which includes the abundance, species composition, metabolism, and condition of indigenous aquatic organisms. Standardized methods for sample collection and preparation are widely available. However, additional tools are urgently needed to assist biologists in sample analysis and data interpretation. The tools needed include species identification manuals, information on the life histories of aquatic organisms, and descriptive models with which to evaluate field data. The models would describe the standing crop, species composition, and community metabolism expected at a given sampling station in the absence of pollution, taking into account the season of the year, climate, ambient meteorological and hydrological conditions, water chemistry, and the nature of the substrate. Effective data interpretation also requires utilization of available parametric and nonparametric methods for statistical analyses of the field data in order to determine the significance of observed differences in the properties of aquatic communities at “control” and “polluted” sampling stations.
Environmental Impact Analysis of Aquatic Ecosystems Using Rational Threshold Value Methodologies
Authors: Herricks EE , Sale MJ , Smith ED
Published: March 2009

The techniques generally applicable to environmental impact analysis fall short of effective predictive capacity because of incomplete data bases and the lack of procedures for systematic data analysis to maximize data utility. To overcome these difficulties, the Construction Engineering Research Laboratory of the Department of the Army has developed a computer-based environmental impact analysis system. As part of this continuing activity, the Environmental Impact Computer System (EICS) has been used as a basis for development of a detailed subprogram for predicting impacts on aquatic ecosystems. The EICS system is based on the development of methodology for determination of rational threshold values (RTV). RTV includes indexes of both structural and functional community conditions that are integrated into a decision algorithm. Data for community parameters are obtained from readily available resources [STORET, National Pollution Discharge Elimination System (NPDES) permit reporting, and other state and federal water-quality monitoring efforts], system subprograms that provide population predictions based on state-of-the-art population models, and actual field data. The protocols described include interactive, real-time manipulation of data based on site-specific information. The application of these protocols provides a new dimension in impact analysis methodology. Ecosystem-specific threshold levels can be set, and impacts caused by alternatives can be evaluated efficiently and economically. This paper summarizes aquatic ecosystem RTV analysis procedures, discusses feasibility of application, and provides a sound quantitative approach to priority ordering of community parameters for aquatic ecosystem impact analysis.
Method for Evaluating the Impact of Radioactivity on Phytoplankton
Authors: Gertz SM , Suffet IH
Published: March 2009

Concentration factors are often used to assess the impact that radionuclides may have on aquatic organisms. The use of literature values or even measured concentration factors may not be appropriate for a given situation, since these factors are dependent on many environmental parameters. However, if the environmental stresses that affect a concentration factor are known and quantified, a better and potentially more efficient estimate of impact assessment can be made. The authors report here the use and results of a laboratory technique that could be used to evaluate the environmental impact of radioactive effluents on phytoplankton.

The target alga is Chlamydomonas reinhardii, a common green flagellate that is amenable to growth in the laboratory. The model radionuclide is cesium-137, an important constituent of the radioactive liquid effluents from nuclear power plants. The organisms are grown in a chemostat, which consists of four growth chambers. The chemostat allows algae to be maintained in their log growth phase while various environmental parameters are manipulated. It was found that the cesium-137 concentration factors are controlled by the phosphate concentration, the sodium concentration, and the algal biomass. Temperature, algal reproduction rate, potassium concentration, and chloride concentration have no effect on the observed concentration factors. The cesium concentration factor ranges from 115 to 586 on a dry weight basis under the various environmental conditions studied.
Effects of Exposure Time, Season, Substrate Type, and Planktonic Populations on the Taxonomic Composition of Algal Periphyton on Artificial Substrates in the Ohio and Little Miami Rivers, Ohio
Authors: Weber CI , McFarland BH
Published: March 2009

Standard glass microscope slides were exposed at the surfaces of the Ohio and Little Miami Rivers at Cincinnati, Ohio, for 1, 2, 4, and 8-week periods in June through November 1966. The maximum cell densities were attained in samples from the Little Miami River after an exposure of 1 or 2 weeks, except in November. In the Ohio River, the maximum counts were observed after exposures of 4 weeks in June and July, and 1 week in August and September. In October and November, the cell density continued to increase with increasing periods of exposure.

Distinct successional patterns in the composition of the periphyton populations were not found. The changes in the composition of the periphyton with increased substrate exposure time resulted principally from seasonal changes in environmental conditions and phytoplankton populations.

The maximum algal cell density, 29 000/mm2, was observed in a 1-week sample collected in the Ohio River. The periphyton populations in both rivers were generally dominated by diatoms, which averaged 68 percent of the cell count. The most important genera were Achnanthes. Cyclotella, Gomphonema, Melosira, Navicula, Nitzschia, Stephanodiscus, and Synedra. Other important groups were the green flagellates and filamentous blue-green, coccoid green, and filamentous green algae.

The biomasses on five sets of glass and Plexiglas slides exposed for 2 weeks in the Little Miami River during the period of August through November did not differ significantly.
Various Methods Used in Evaluating the Quality of Oil-Field Waters for Subsurface Injection
Authors: Strickland LN
Published: March 2009

A variety of tests are required in order to determine the quality of water in subsurface injection operations. Water analyses, scaling tendencies, compatibility of mixed waters, residual hydrocarbon content, oxygen content, presence of bacteria, corrosion resulting from the water(s), and the type and quantity of suspended solids must be determined in order to evaluate the water quality for subsurface injection. Most of these tests must be conducted in the field with some additional tests conducted in the laboratory.
Wear Testing—Correlation with End-Use Performance
Authors: Eiss NS
Published: March 2009

The failure modes of a plastic involved in sliding motion are presented. The mechanisms of loss of plastic material by wear are discussed. These mechanisms include adhesive wear, in which the transfer-back transfer process occurs, abrasive wear in which loose debris particles are produced directly from the sliding action, fatigue wear which is often the mechanism by which transferred films wear, and degradation wear which results from interface temperatures high enough to decompose the plastic. Common tests, such as the abrasive wear test (ASTM D 1242-69) and the Pressure Velocity (PV) test are described, and the limitations in correlation with end use are noted. Suggestions are made which will improve the correlation between tests and end use.
Present State of U.S. Ferroalloy Industry
Authors: Gate AD
Published: March 2009

This paper describes the major ferroalloys of chromium, manganese, and silicon, and examines the ferroalloy industry, its special needs, and its problems. The major producers and the market they serve are listed, and the manufacturing procedure and the materials required are illustrated. Sources of materials and their changing availability are reviewed along with geopolitical influences and their effects on domestic industry. Trends, short and long term, and what we can expect in the future conclude the presentation.
Control of Ferroalloys in a Large Integrated Steel Mill
Authors: Peters AT
Published: March 2009

The development of alloy purchasing specifications is reviewed along with the control of incoming materials for their chemistry and sizing, and the disposition of marginal shipments. Minimum alloy input is determined and an actual calculation of alloy requirement of a heat of steel is made using a simplified formula. Computerized input calculations for lowest-cost alloy mix are made, as well as computerized and manual checks of actual versus planned alloy input and performance. Finally, new alloy practices and their dependence on required steel quality are determined, and examples given of minimizing the cost/benefit ratio regardless of alloy cost.
Properties and Uses of Alloy Additives for the Modification of Cast Iron
Authors: Lalich MJ , Glover WD
Published: March 2009

Foundrymen have long recognized the value of adding special additives to gray and ductile cast irons to modify structure and control properties. While graphite growth mechanisms are better understood today than just a few years ago, comprehensive theories have yet to be established and accepted. Nevertheless, efforts to comprehend and control the inoculation and nodularizing processes have resulted in a variety of products and treatment techniques. This paper endeavors to summarize the present status of the alloys used to modify cast iron.

A very diverse product line of inoculants exists in today's market. While most inoculants are based on ferrosilicon and contain some aluminum and calcium, they may also contain barium, titanium, strontium, rare earths, or other elements.

The method of addition, as well as the location and time of addition of special alloys to cast iron, plays a prominent role in determining the addition levels and the effectiveness of a particular treatment. For example, inoculants may be added to the ladle, or later in the process as the metal stream enters the mold, or in the mold itself. Inoculants used in the ladle are normally added in the stream entering the ladle and are usually granular in nature. In late inoculation, on the other hand, the inoculant may be added as a powder, an encapsulated powder, or a bonded or cast insert. Today, the bulk of inoculants are added in the ladle. However, due to metallurgical and economical considerations plus production restrictions, the practice of late inoculation has grown in recent years.

The nodularizing treatment for ductile iron is commonly accomplished by ladle treatment with magnesium-ferrosilicon alloys. A variety of other additives, including pure magnesium, is finding use. Recently, particularly in the automotive industry, many foundries have begun to convert to the Inmold Process.

Efforts are currently being made within the foundry industry to produce an intermediate iron to gray and ductile iron, known as compacted graphite iron. At least one additive is available commercially for this purpose.
Potential Dependence of Localized Corrosion in Iron
Authors: Toušek J
Published: March 2009

Two passivating potentials, EF1 and EF2, can be observed for iron in chloride containing media. From the existence of these two passivating potentials the existence of two breakdown potentials follows: the first breakdown potential, Eb1, and the second breakdown potential Eb2. In the regions immediately positive to these potentials, the rate of localized corrosion (that is, the total current density and the number of pits) rises exponentially with the potential. According to the solution composition, the current density in the pits is potential independent or obeys the exponential dependence.
A Method for Quantifying the Initiation and Propagation Stages of Crevice Corrosion
Authors: Lee TS
Published: March 2009

An electrochemical approach for investigating crevice-corrosion initiation and propagation phenomena is discussed. The method varies from previous ones in that it is applicable in natural environments and requires no artificial stimulation. Quantitative measurement of electrochemical parameters provides a basis for further understanding the nature of crevice corrosion.

The test technique allows measurement of time to initiation and rate of propagation of crevices. This is achieved by electrically coupling a small test specimen (Anode) through a zero-impedance ammeter to a larger specimen (cathode). Both specimens are immersed in an electrolyte and the anode is “sandwiched” between two nonmetallic plates. This creates a crevice. The current between the cathode and the anode is monitored as a function of time.

Data are reported for Types 304 and 316 stainless steel exposed in natural seawater. Times to initiation and propagation rates as determined from current measurements are compared with visual observations of times to initiation and gravimetrically determined propagation rates.

The ability to determine a “protection” potential to prevent crevice corrosion is reviewed, and the utility of the technique in evaluating the effects of alloy and environmental variables on crevice corrosion is discussed.
Corrosion and Electrochemical Behavior of Iron-Chromium-Nickel Alloys in Concentrated Sulfuric Acid Solutions
Authors: Tong HS
Published: March 2009

The electrochemical and corrosion behavior of Types 304 and 316 stainless steels and Carpenter 20 Cb-3 alloy in 99 percent sulfuric acid solutions have been investigated at temperatures up to 127°C. The open-circuit potentials (OCP) have been monitored against immersion time. Oscillations of the OCP at high temperature were observed in some cases. Correlation between OCP-time behavior and corrosion resistance has been established. Metallurgical studies have been carried out for alloys after each test. Changes in the corrosion behavior on the alloy surfaces as a function of temperature and solution concentration were observed.

The corrosion rate of each alloy/medium system has been determined by the conventional weight-loss measurement. Comparison of the corrosion resistance among three alloys has also been made. Corrosion rate was found to increase with increasing temperature, stirring rate, and iron content in the solution.
A Corrosion Monitor Based on Impedance Method
Authors: Haruyama S , Tsuru T
Published: March 2009

Theoretical and experimental studies were performed on the impedance characteristics of corroding metal with the aid of a new a-c corrosion monitor. According to the theory of impedance of a mixed potential electrode, the subtraction of the impedance at a high frequency from that at a low frequency yields, in most cases, transfer resistance that is readily reduced to the corrosion rate of the electrode (if an appropriate selection of the two frequencies has been made). By using a superimposed signal of two a-c voltages of 10 kHz and 0.01 Hz, the a-c corrosion monitor was designed to yield either transfer resistance or corrosion current on a recorder in logarithmic scale. The monitor permitted the measurement of the corrosion rate in less-conductive environments, such as tap water, distilled water, and soil. Initiation of localized corrosion was also detected in most cases by a sharp increase in corrosion current. The corrosion currents obtained with the a-c corrosion monitor and by the weight-loss measurement gave a good correlation on various metals under various environments, which cover corrosion rates of 15 to 0.0007 mm/year.
Use of Titanium and Zirconium in Chemical Environments
Authors: Kane RD , Boyd WK
Published: March 2009

Titanium and zirconium are playing an increasingly greater role in industry as corrosion-resistant materials for use in severe environmental conditions. Their applications in a variety of environments are reviewed. Discussion also focuses on potential new areas where titanium and zirconium can be expected to find application because of their mechanical and corrosion-resistant properties.
Use of Zirconium Heat Exchangers in the Viscose Rayon Process
Authors: Bowen LB
Published: March 2009

Zirconium tubed heat transfer equipment has been used successfully in the viscose rayon process since 1970. Heating coils are used to heat sulfuric acid solutions to 373 K, shell-and-tube and bayonet heat exchangers to heat spinning baths to 343 K, and thermosiphon evaporators to remove water from spent spinning bath solutions. Energy usage and heat exchanger maintenance costs have been reduced as a result of converting to zirconium tubed heat exchangers. High concentrations of sulfuric acid were found above plugged tubes in three evaporators. This acid, which is corrosive to zirconium, destroyed one heat exchanger. By increasing the liquid level height to flood the top tube sheet, the plugging rate was reduced, thus eliminating the corrosion.
Applications of Zirconium in Sulfuric Acid
Authors: Schemel JH
Published: March 2009

Zirconium is an economically attractive material for use in sulfuric acid at combinations of temperature and concentration beyond the capacity of stainless steels and silicon-iron alloys or where very low corrosion rates are desirable. This paper defines the range of application and illustrates through case histories the problems encountered in successfully using zirconium in this medium.

The corrosion of zirconium in sulfuric acid is characterized by very low corrosion rates over a wide range of temperatures and concentrations, but it is bound at the upper end of the range by an abrupt increase in rate over an increase in concentration of only a few percentage points. This paper treats the steps in successful application from a thorough knowledge of the plant solution, through the rigors of proper testing in both laboratory and service, to the construction of process equipment.

Laboratory test data that use a variety of alloys as well as unalloyed zirconium in a range of test conditions define the basic area of application. The mechanisms of the corrosion process and the precautions needed to ensure valid test results are discussed.