bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Energy Neutron Dosimetry of a Spallation Neutron Source
Authors: Hegedüs F , Green WV , Stiller P , Green S , Herrnberger V , Stiefel U , Victoria M 
Published: December 2008

High energy spallation neutron sources may be used for radiation damage experiments on first-wall candidate materials of fusion reactors. In these experiments the neutron spectrum and the helium production rate must be measured at the location of material samples in the irradiation facility.
The planned spallation neutron source (SINQ) at the Swiss Institute for Nuclear Research (SIN) was simulated by using the 500 MeV proton beam of the TRIUMF accelerator in Canada and its molten lead beam stop as the source of spallation neutrons.
The neutron spectrum was measured by the multiple foil activation method. A set of foils (Al, Sc, Ti, Fe, Co, Ni, Cu, Zr, Nb, In, Tm and Au) was irradiated at several locations around the molten lead source. A total of 37 reactions were available with product nuclei suitable for Ge (Li) gamma spectroscopy. The neutron spectrum was obtained by unfolding procedure using the SANDA code. As neutron activation cross section libraries are not available in Europe, in the energy range above 20 MeV, it was necessary to develop and construct a new library.
The helium accumulation in Fe, Al, Cu, Zr, Ti and W was measured by means of a Rock-well International mass spectrometer.
Analysis of Solid-State Track Recorders with the Westinghouse Research and Development Center Automated Track Counter
Authors: Ruddy FH , Manhardt AE , Seidel JG 
Published: December 2008

A new automated image analysis system for counting neutron-induced fission fragment tracks in mica solid-state track recorders (SSTRs) has been developed and is in use at the Westinghouse Research and Development Center. This computer-controlled optical microscope uses state-of-the-art image enhancement and pattern recognition techniques to identify tracks. Track pile-up corrections have been eliminated for track densities up to 8 × 105 tracks/cm2.
The system has been absolutely calibrated to better than 2% uncertainty in the track density range from 1 × 104 tracks/cm2 to 8 × 105 tracks/cm2. The track counting efficiency is independent of local track density variations over this range.
Key scanning parameters are stored on a microscope field of view by field of view basis and form a part of the long-term Quality Assurance records for SSTR analysis.
Spectrum Measurements on Filtered Neutron Beams for Medical Applications
Authors: Constantine G , Brenen A , Moore PGF , Perks CA 
Published: December 2008

Boron neutron capture therapy involves thermal neutron irradiation following preferential incorporation of boron by 10B-loaded tumor-seeking drugs. Attenuation precludes deep-seated tumor treatment using incident thermal neutrons. Attention is now being focused on epithermal/intermediate neutrons subsequently moderated in tissue to give a more uniform flux distribution, suitable for brain tumor therapy.
Choice of incident neutron energy is critical because the proton recoil damage is indiscriminate. Following irradiations of various biological cell lines in vitro with and without boron perfusion in our iron-filtered 24.5 keV beam, we have developed an argon/aluminum/sulfur/filtered broad spectrum beam. The paper describes our proton recoil spectrometry for the &gt; 10 keV range and determination of the spectrum below that using spectrum modifiers such as 10B, V, and Ti. The adjustment code SENSAK was used to obtain our best estimate of the beam spectrum, from which a mean energy of 9.8 keV was derived.
Personnel Neutron Dosimetry Area Monitoring Using Solid-State Track Recorders
Authors: Ruddy FH 
Published: December 2008

Personnel neutron dosimeters using a number of different techniques have been developed for routine use in neutron fields, but all of these dosimeters must be carefully corrected to account for the fact that their response is critically dependent upon the energy distribution of the neutron field. At present, personnel neutron dosimeters are typically calibrated in a standard neutron field (e.g., 252Cf or D2O-moderated 252Cf)- but may then be applied in neutron fields that vary considerably from the calibration field. Some widely used personnel dosimeters, such as TLD-albedo dosimeters, overrespond to low energy neutrons and therefore deliver high readings in fields that are more moderated than the standard field.
The solution to the problems created by this energy dependence of the calibration of personnel neutron dosimeters is to obtain accurate experimental information on the neutron energy spectra in the fields to which the personnel dosimeters will be exposed. This paper discusses an effective and accurate means to obtain this information by the application of solid-state track recorder neutron area monitors.
Project and Problem Definition in Building Air Quality Investigations
Authors: Allard PF 
Published: December 2008

Building air quality investigations can involve a variety of organizational interests and technical interactions that are not always recognized by those requesting an investigation. In order to be effective, field investigators must determine if the parties who are responsible for and affected by a problem building understand the complexity and subtlety of the potential causes, and, if they do not, be prepared to provide education and a frame of reference to help them to approach a common level of understanding. A general approach is needed for the preparation of the managers and occupants of commercial buildings for involvement in an indoor air quality investigation.
A common difficulty is an initial lack of appreciation of the range of interests, causes, interactions, and responsibilities which can be involved in the investigation and solution of an indoor air quality problem. These issues are discussed and outlines are presented for use in project and problem definition.
Indoor Air Quality Diagnostics: Qualitative and Quantitative Procedures to Improve Environmental Conditions
Authors: Woods JE , Morey PR , Rask DR 
Published: December 2008

Procedures conventionally used in industrial hygiene are often inappropriate for application in non-industrial environments. More sensitive procedures are needed, since comfort, occupant well-being, and general population susceptibilities are parameters not now addressed by occupational threshold limit values (TLVs). A common result is that compliance with industrial hygiene standards may be demonstrated, but complaints from occupants persist. A new discipline, building diagnostics, is useful in addressing these more sensitive parameters. An application of this discipline to the evaluation of indoor air quality is presented in this paper.
A fundamental aspect to building diagnostics is the need to understand the relationships that exist between the building, its systems, and its occupants. This understanding is developed initially through qualitative diagnostics in which the scope of investigation is defined, appropriate environmental performance criteria are determined, the nature of any existing complaints is reviewed, and an engineering assessment of the HVAC system is conducted. From these qualitative data, a set of hypotheses is developed in terms of the inadequacies of the performance or the opportunities for improvement. Based on these hypotheses, system performance under various loads is predicted and ways to mitigate and improve performance are recommended. An important advantage of this approach is that many problems can be solved at this stage before measured data are required.
However, in some cases, objective and subjective measurements may be required to confirm hypotheses and to substantiate or modify the previous recommendations. In these cases, quantitative diagnostics is indicated. Because of the cost involved in this phase, measurement locations must be identified carefully. We find that five locations in a functional area of the building are sufficient to characterize system performance and occupant response: locations of least ventilation effectiveness, strongest contaminant source, most susceptible occupants, a “control location,” and an outdoor location. Only those quantitative measurements appropriate to the hypotheses are taken; these may include air quality, thermal, lighting, and acoustics parameters. Simultaneously, questionnaires are also used to measure human responses to the environmental conditions within the occupied spaces. These quantitative data are analyzed for compliance with the performance criteria. Recommendations for modifications are then made which address employee concerns, architectural concerns, and cost-effective operation.
Skiing Trauma and Safety: Seventh International Symposium
Authors: Johnson RJ , Mote CD , Binet M-H , Binet M-H 
Published: December 2008

Description
Research findings and expert opinion on the problem of snow skiing injury. 39 papers cover: epidemiology of skier injuries; skier behavior, ability, and conditioning; specific skier injuries; ski boot mechanics; binding mechanics; biomechanics of the lower extremity in skiing; biomechanics of thumb injuries; skiing safety; biomedical testing; and clothing.
Automated Procedure for Creating Flight-by-Flight Spectra
Authors: Denyer AG 
Published: December 2008

This paper presents a functional description of a versatile computer program developed to provide rapid response to spectrum generation requirements. The program, when supplied with flight profiles and the distribution of those profiles during the aircraft lifetime, will create a randomly sequenced flight-by-flight spectrum in terms of load factors, loads, or stress at a specific structural location.
The heart of the program is a data base containing the frequency definition of load factor occurrences representing the gust and maneuver load cycles for various flight segments. This paper discusses the establishment of the data base from data published in MIL-A-87221 and the FALSTAFF reports, from analytically derived load factor data and from flight load records from specific aircraft. The various forms of load factor data acceptable to the program, namely, exceedance curves, range/mean tables, and the FALSTAFF methodology, are discussed as to advantages and disadvantages.
The program will accept multiple flight profiles each with multiple flight segments defined by segment title, segment time, and selected significant flight parameters such as gross weight, Mach number, altitude, and aircraft geometry. For each profile, the procedure creates a series of individual flight load factor spectra each of which differs from all others in load sequence and magnitude while maintaining the sequence of the flight segments. The spectra include the infrequent high loads randomly selected from within the statistics of the data base. Load-factor spectra to stress spectra conversion is briefly discussed in terms of the program capability.
The output spectrum is a series of flights representing a defined period of usage with the flights representing the various profiles randomly sequenced within the supplied distribution statistics. The spectrum form is suitable for direct input to fatigue or crack growth programs or can be output to tape for submittal to a fatigue testing machine.
The Brooker-Wills Femoral Nail: Technical Difficulties and Their Avoidance
Authors: Blumberg KD , Hanks GA , Foster WC , Cardea JA 
Published: December 2008

Eighty-seven femur fractures treated with the Brooker-Wills distal fin deployment interlocking nail were analyzed for intraoperative technical problems. Only unstable fractures located distal to the lesser trochanter and proximal to a level 5 cm proximal to the distal epiphyseal scar were included. Seventeen fractures were subtrochanteric, 19 were comminuted diaphyseal, and 51 were subisthmal. The majority (73) were locked proximally and distally. Of the 87 procedures, 33 technical difficulties occurred in 24 cases, for an overall rate of 29%. These ranged from problems with fin deployment and proximal screw insertion to bending of the nail itself. Patient position and proper technique were significantly correlated with the incidence of technical difficulties.
Postoperative complications were few, with one angulatory malunion, five nonunions, two unacceptable shortenings, and no deep wound infections. Average healing time was 12 weeks. The nail functioned well in regard to fracture healing, which was not affected by the technical difficulties. A significant learning curve for nail insertion was demonstrated. The authors concluded that most of the problems encountered could be avoided by strict adherence to suggested technical details and lateral patient positioning.
Assurance of the Pressure Vessel Integrity with Respect to Irradiation Embrittlement: Activities in the Federal Republic of Germany
Authors: Kussmaul K , Fëhl J , Weissenberg T 
Published: December 2008

Safety research of light water reactor pressure vessels in the Federal Republic of Germany (FRG) is presently focused on validation programs based on fracture mechanics concepts which study irradiation embrittlement, pressurized thermal shock, and cyclic crack growth under operating conditions. Crack initiation values derived from the JR-curve could be confirmed as reliable material property to enable transferability of results from small specimen testing to complex structures.
For validation of irradiation surveillance practice, trepans were taken from a forged shell course of a commercial reactor pressure vessel wall to compare material degradation of the wall with that of the surveillance specimens and to establish properties through the thickness of the wall. The experimentally determined amount of reduction in toughness of the vessel wall depends strongly on the orientation of the specimens with respect to the main forging direction of the hot formed material. The degradation of the material with respect to transition temperature shift and upper shelf energy drop in Charpy impact tests could not be predicted conservatively on the basis of the existing trend curves in the U.S. Code of Federal Register. On the other hand, the gradient of embrittlement measured in short distances from the inner to the outer surface of the vessel wall is much less and therefore less important than assessed in the proposed revision of the U.S. Code.
Archive material representing the shell course from which the trepans were taken was irradiated in test reactors in the United States and the United Kingdom. The irradiated archive material shows a lower degradation than the vessel wall of the commercial reactor.
The Swiss Research Program on Irradiation Embrittlement and Annealing of Reactor Pressure Vessel Steels
Authors: Waeber WB , Njo DH 
Published: December 2008

The present research program on irradiation embrittlement and annealing of reactor pressure vessel (RPV) steels in Switzerland is carried out at the Paul Scherrer Institute for Reactor Research. The particular program structure and its relation to the concept for an improved surveillance program is described.
Based on past experience with surveillance programs, especially for older plants, the main goal of the research program is determined by an effort to overcome identified shortcomings.Therefore the following topics are discussed: 1. Obtaining additional data to supplement those from specific surveillance capsules. 2. Understanding the mechanisms of irradiation embrittlement by microstructural investigations of the materials. 3. Investigations of the annealing-recovery behavior of irradiated RPV steels. 4. Validation efforts concerned with the transferability of test reactor and surveillance program results to the real RPV.
Within the framework of bilateral research agreements, participation in research programs coordinated by the International Atomic Energy Agency (IAEA), and collaborative research with other Swiss and foreign institutions, a review of past and future activities is presented; the technical facilities (irradiations, mechanical testing, physical methods) and the advanced and new tools used in the investigations, especially those for the microstructural studies, are outlined and put into perspective. Finally, first results obtained in the research program are summarized.
Development of Reactor Pressure Vessel Design, Neutron Fluence Calculation, and Material Specification to Minimize Irradiation Effects
Authors: Leitz C , Koban J 
Published: December 2008

In the second decade of design and construction of water-cooled and watermoderated power reactors in the Federal Republic of Germany (FRG), the neutron irradiation effect on reactor pressure vessels (RPV) was reduced in a twofold manner: 1. Steel optimization for high toughness at the end of design life. 2. Fluence reduction by adaptation of core geometry and RPV diameter.
The methods of fluence evaluation and results for different core configurations are described. They provide a satisfactory fluence surveillance of the RPV. If necessary, operational measures are possible to reduce the end of life (EoL) fluence of the RPV. The provident fluence reduction measures taken in two older commercial power plants are described. These measures reduced the EoL fluence by more than a factor of two without loss of power.
The new generation RPV provides a larger water gap between core edge and RPV wall and therefore much lower EoL fluences. The design EoL fluence of all 1300-MWe and the modern 1000-MWe PWR is 5 × 10 18 cm -2 and 3.3 × 10 18 cm -2, respectively.
Fine-grain forged steels 22 NiMoCr 3 7 and 20 MnMoNi 5 5 and corresponding weldments are used for the RPV in KWU-built nuclear power plants. Extensive experience has been gained on the irradiation behavior of these steels. By specifying high purity, especially for the elements copper (Cu) and phosphorus (P), and by keeping Nickel (Ni) at medium levels, which improves preirradiation toughness but supports irradiation effect, high postirradiation toughness is maintained.
Therefore, in combination with the low EoL neutron fluences, the nil ductility transition temperature shift Δ T 41 was reduced by nearly 90% by comparison with the first generation plants (high fluence, high copper).
Effects of Matrix Toughness on Fatigue Response of Graphite Fiber Composite Laminates
Authors: Simonds RA , Bakis CE , Stinchcomb WW 
Published: December 2008

To evaluate the possible advantages of using a tough resin, polyetheretherketone (PEEK), as a matrix in a composite material, the fatigue response of (0/ +45/90/ −45)s4 AS4/ PEEK graphite-epoxy specimens with drilled center-holes subjected to constant amplitude, fully reversed cyclic loading was investigated. The results were compared with those of a similar investigation using T300-5208 graphite-epoxy specimens to determine the effects of matrix toughness on fully reversed fatigue.
Several load levels provided for lives between 104 and 107 cycles to establish baseline (R = − 1) S-N curves for the two materials. Additionally, damage evaluation methods such as stiffness monitoring, penetrant-enhanced radiography, and residual strength measurements were used to identify damage mechanisms; to monitor damage growth process; and to establish relationships between damage and strength, stiffness, and life of the specimens.
Damage initiated at the hole in all cases, but the damage modes, their subsequent growth and interaction, and their effects on fatigue response were dependent on cyclic load levels and material. Damage in the brittle 5208 matrix specimens consisted of matrix cracks followed by delamination. Over the range of fatigue lives studied, the residual tensile strengths of the 5208 matrix specimens were greater than the initial notched tensile strength. During loading the compressive strength degraded to values less than initial notched compressive strength, and the fatigue failure modes were compressive. Similarly, at the lower cyclic load levels, corresponding to lives between 105 and 107 cycles, the PEEK specimens also suffered matrix cracking, delamination, and an attendant compressive stiffness loss. The specimens failed under the compressive portion of the cyclic loading. However, at higher cyclic loads, 0° fiber damage in the PEEK specimens was observed in addition to matrix damage, and the tensile stiffness degraded. The failure modes were tensile in these cases.
The results of this study show that matrix toughness influences the long-term behavior of graphite fiber composites. Although similar matrix damage modes were observed in the two material systems, the consequences of the damage, as measured by strength, life, and failure mode, were not similar.
Consideration of Environmental Conditions for the Fatigue Evaluation of Composite Airframe Structure
Authors: Berg M , Gerharz JJ , Gökgöl O 
Published: December 2008

This paper reports on experimentally derived compensation factors to account for missing environmental history (temperature and humidity) during fatigue testing of large composite structures (components). Compensation factors are either factors by which the fatigue load level of component fatigue tests is increased or by which the required residual strength has to be increased if preloading did not include environmental history.
Preconditioned coupon specimens were subjected to accelerated quasirealistic mechanical and environmental flight-by-flight loading, and other coupon specimens were loaded exactly like the composite airframe structure (that is, with less complete simulated environment). Temperature and moisture content in residual strength testing were the same for surviving coupon specimens and the composite airframe structure. Corresponding to composite airframe structures of the Tornado and the Airbus fin box, the materials involved were the 175°C curing systems Ciba 914C and Fiberite 1076 E, and the 125°C curing systems Ciba 913C and Hexcel F550 with T300 carbon fibers in all resins. Different types of laminates and specimens were used to generate predominantly matrix shear stresses or fiber normal stresses within the coupon specimens.
At present design load levels, the fatigue life to be proven was reached without failures of the coupon specimens subjected to the flight-by-flight load conditions of the component test or to quasirealistic combined mechanical and environmental loading. Only small differences in residual strength were noticed among the surviving specimens. At higher fatigue load levels the superimposed more complete environmental test conditions decreased the life to failure significantly, by factors between 1.5 and 9.1.
Delamination Damage in Central Impacts at Subperforation Speeds on Laminated Kevlar/Epoxy Plates
Authors: Malvern LE , Sun CT , Liu D 
Published: December 2008

An experimental research program has shown that in central impacts at normal incidence by small hard impactors at subperforation speeds on continuous-filament fiberreinforced, laminated composite plates with brittle matrices, the major damage is delamination at the interfaces between unidirectionally reinforced layers of different orientation. This is accompanied by some matrix cracking between the fibers of the layers.
Composites with three kinds of fibers (glass, Kevlar, and graphite), each in a brittle epoxy matrix, have been investigated. This paper reports new results on Kevlar and compares them with some previously published results on glass and graphite. Postimpact visual examination of the semitransparent glass and Kevlar laminates revealed the extent of the delamination.
Relationships between projected delamination area and the kinetic energy imparted to the plate are reported. For those plates where the overlapping delaminations could be resolved and the total delamination area could be determined, the evidence supports the assumption of a single linear relation between total delamination area and imparted kinetic energy for each system observed at these subperforation speeds, but there is a limited amount of this kind of data available. Bending strength and stiffness reductions of the damaged panels are also reported.