bluuebunny/crossref_metadata_2025 huggingface dataset:
Patients' Perceptions of Information Received at the Start of Selective Serotonin-Reuptake Inhibitor Treatment: Implications for Community Pharmacy
Authors: Geffen Erica CG van , Kruijtbosch Martine , Egberts Antoine CG , Heerdink Eibert R , Hulten Rolf van
Published: March 2009

Background:

Pharmacists are increasingly acknowledging their responsibility to inform and counsel patients. However, it is unclear how these tasks are implemented and whether patients' needs are being fulfilled.

Objective:

To examine patients' perceptions of information received at the start of selective serotonin-reuptake inhibitor (SSRI) treatment, aiming to identify (1) information needs and (2) the potential role of the community pharmacist as information provider.

Methods:

A qualitative descriptive study comprising semi-structured telephone interviews was carried out with patients who had recently started a new course of SSRI treatment. Patients were recruited through 6 Dutch community pharmacies. The interviews were guided by the following topics: type of information obtained, unmet information needs, preferred information provider, and the role of the pharmacist.

Results:

Forty-one patients took part in an interview. Information needs varied widely among patients; overall, patients felt that they would benefit from information tailored to their needs. Many patients required more concrete and practical information on adverse effects and delayed onset of action than was provided. In addition, an explanation of the term dependency in the context of SSRI use and a discussion of the necessity for use and believed harms of long-term treatment were important to patients. Regardless of patients' needs, the role of the pharmacist was generally perceived as limited, and patients identified several pharmacy-related barriers to improved communication, including the timing of information (mainly restricted to first-time dispensing), lack of time and privacy, lack of empathy and a protocol-driven way of providing information, and inexperience of pharmacy technicians.

Conclusions:

Patients starting treatment with antidepressants may benefit from information tailored to their personal needs. Along with the prescribing physician, community pharmacists could have an important role in informing and counseling patients.
Psychopathy, frustration, and reactive aggression: The role of ventromedial prefrontal cortex
Authors: Blair R. J. R.
Published: March 2009

Psychopathy is a developmental disorder marked by emotional hyporesponsiveness and an increased risk for instrumental and reactive aggression. The increased risk for reactive aggression is the focus of the current paper. It will be argued that the increased risk for reactive aggression does not relate to an increased sensitivity to threatening stimuli since psychopathy is associated with a reduced sensitivity to threat. Instead, it is argued that the increased risk for reactive aggression relates to an increased risk for frustration; i.e., the emotional state following the performance of an action in the expectation of a particular reward and not receiving this reward. Two impairments seen in psychopathy would increase the risk for frustration and consequent potential reactive aggression; impairments in stimulus‐reinforcement learning and reversal learning. It is argued that both are known consequences of impairment in ventromedial prefrontal cortex, one of the regions principally implicated in psychopathy.
Visuographic tests of set shifting and inhibitory control. The contribution of constructional impairments
Authors: Diesfeldt H. F. A.
Published: March 2009

Luria's graphical or alternating sequences test (the ‘rampart’ design) is a well‐known procedure to examine attentional processes such as set shifting and inhibition of competing responses. Although the test requires attentional control over inappropriate responses, it also relies on constructional abilities that may hamper the specificity of the test. In order to control for the influence of constructional abilities, the structural equation modelling (path analysis) was used to examine the correlations between the performance on alternating sequences and an independent criterion measure of executive functioning (the Behavioural Dyscontrol Scale), corrected for the influence of visuoconstructional ability as reflected by performance on a task of design copying. The tests were administered to 950 elderly participants in a psychogeriatric day‐care programme. Performance on the Behavioural Dyscontrol Scale (BDS) and the copying tasks jointly predicted performance on the alternating sequences test (AST) (multipleR2=.41). Though the effect of BDS on AST was 38.9% mediated by constructional ability, BDS scores predicted performance on graphical sequences above and beyond the influence of drawing ability. In a non‐parametric classification tree analysis, the performance on the AST was reliably predicted by drawing ability. When BDS performance was added to the analysis, the classification accuracy increased for participants with poor drawing, but remained unchanged for those who performed in the normal range on the copying tasks. As a task that relies on shifting and inhibitory control, the alternating sequences test is a feasible measure of executive functioning that is relatively independent of the influence of the component drawing skills.
High-Throughput Analysis of Sphingosine 1-Phosphate, Sphinganine 1-Phosphate, and Lysophosphatidic Acid in Plasma Samples by Liquid Chromatography–Tandem Mass Spectrometry
Authors: Scherer Max , Schmitz Gerd , Liebisch Gerhard
Published: March 2009

Background: Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are ubiquitous lipid messengers found in the blood and most cell types. Both lysophospholipids are ligands of G protein–coupled receptors and mediate important physiological processes. Moreover, lysophospholipids are potential biomarkers for various diseases, including atherosclerosis and cancer. Because existing methodologies are of limited value for systematic evaluations of S1P and LPA in clinical studies, we developed a fast and simple quantification method that uses liquid chromatography–tandem mass spectrometry (LC-MS/MS).

Methods: Sphingoid base 1-phosphates and LPA species were quantified in negative-ion mode with fragments of m/z 79 and 153, respectively. The internal standards LPA 17:0 and [13C2D2]S1P were added before butanol extraction. Application of hydrophilic-interaction chromatography allowed coelution of analytes and internal standards with a short analysis time of 2.5 min.

Results: Comparison of butanol extraction with a frequently used extraction method based on strong acidification of human plasma revealed artificial formation of LPA from lysophosphatidylcholine with the latter method. Validation according to US Food and Drug Administration guidelines showed an overall imprecision (CV) of <12% and a limit of detection <6 nmol/L for all lysophospholipid species. Concentrations of S1P and sphinganine 1-phosphate (SA1P) in EDTA-containing plasma were stable for 24 h at room temperature, whereas LPA concentrations increased substantially over this period.

Conclusions: Our validated LC-MS/MS methodology for quantifying LPA, S1P, and SA1P features simple sample preparation and short analysis times, therefore providing a valuable tool for diagnostic evaluation of these lysophospholipids as biomarkers.
Through the learning and teaching looking glass: What do academics in art, design and architecture publish about most?
Authors: de la Harpe Barbara , Peterson J. Fiona
Published: March 2009

What is it that higher education academics in the creative disciplines focus their learning and teaching publications on? Are academics engaging from a contemporary learning perspective in their writing on learning and teaching issues? How prevalent are publications about studio learning
and teaching? In this paper we answer these questions through a review of 118 journal article abstracts published over the last decade in Art, Design and Architecture. We argue that what educators choose to publish about reveals what matters most to them and what they believe would be of interest
to others. While only a relatively few articles were located in peer reviewed journals in these three disciplines and assessment rarely featured, we found consistency in their focus with reform in studio the most likely focus, and self-regulated learning the least likely. The analysis revealed
that many academics are not necessarily using learning and teaching theory to both situate or inform their academic writing on learning and teaching, with aspects of a contemporary learner-centred, theoretically-informed position evident in only just over half of the journal article abstracts
that we reviewed. Despite these observations, we remain convinced that to realize the full potential of theory for practice, increasing engagement with educational literature and further interrogation of learning and assessment practices through the scholarship of teaching and learning (SoTL)
is required. Such engagement would strengthen the theory/practice nexus and advance scholarly teaching in studio, and be of benefit to both learners and teachers.
Reviews
Authors: Jones Garrick , Sagan Olivia
Published: March 2009

Educating Artists for the Future: Learning at the Intersections of Art, Science, Technology & Culture, Edited by Mel Alexenberg (2008) Intellect Books, The Mill, Parnall Road, Bristol, BS16 3JG, T: +44 (0) 1179589917, <ext-link xmlns:xlink="http://www.w3.org/1999/xlink"
ext-link-type="uri" xlink:href="http://www.intellectbooks.co.uk">www.intellectbooks.co.uk. ISBN 978-1-84150-191-8

Passionate Pedagogy: A Will To Learn: Being a Student in an Age of Uncertainty, Ronald Barnett (2007) Maidenhead, Berkshire: McGraw-Hill Education:
Society for Research into Higher Education & Open University Press, 199 pages ISBN-13: 978-033522380-0
Determination of Diffusion Characteristics of Intact Rock Mass: A Critical Evaluation
Authors: Hanumantha Rao B. , Singh D. N.
Published: March 2009

Intact rock mass is the most suitable geological formation for disposing of hazardous wastes. Hence, for safety assessment, establishment of contaminant transport mechanism(s) in/through the rock mass becomes essential. Conventional diffusion cells have been employed by earlier researchers for establishing diffusion characteristics of the intact rock mass. However, due to extremely low porosity of the intact rock mass, the time required for obtaining the “break-through curve” runs into a few months, during which maintaining the ambient conditions becomes extremely difficult. To overcome these limitations, researchers have resorted to accelerated diffusion tests, in the recent past. Several analytical models have been developed by the earlier researchers, which can be employed for determining diffusion characteristics of the intact rock mass. This calls for a comparative study of the diffusion characteristics obtained from these models so as to establish their suitability. With this in view, diffusion characteristics of the intact rock mass of different types were established by conducting accelerated diffusion tests and employing these models. In addition, diffusion characteristics of the intact rock mass were determined based on the concept of cumulative concentration accumulation of ionic species (CCAIS) in the measuring reservoir. It has been found that the models reported in the literature over-predict the diffusion coefficients for the intact rock mass. The superiority of CCAIS model, has been demonstrated by computing the hydraulic conductivity of the intact rock mass and comparing it with the centrifuge modeling results.
A New Derivation of the Perturbation Operator Used in MCNP
Authors: Keith Robert E.
Published: March 2009

A new derivation of the perturbation operator used in the MCNP radiation transport code is presented, and equations are determined to evaluate the change in the response from a perturbation in macroscopic cross section due to the first, second, third, and fourth derivative terms, and the second-derivative cross term. The perturbation operator in MCNP currently can be used to determine the change in a response from the first and second order terms in Taylor expansion due to such a perturbation. The derivation presented here produces expressions that are equivalent to the expressions used in MCNP for the first and second derivative, but are simpler and are in a form that more readily reveals their physical significance. The perturbation operator is particularly useful for sensitivity and uncertainty analysis.
Moisture Buffer Value of Building Materials
Authors: Rode Carsten , Peuhkuri Ruut , Time Berit , Svennberg Kaisa , Ojanen Tuomo
Published: March 2009

When building materials are in contact with indoor air they have some capacity to moderate the variations of indoor humidity in occupied buildings. But, so far, there has been a lack of a standardized quantity to characterize the moisture buffering capability of materials. It has been the objective of a recent Nordic project to define such a quantity, and to declare it in the form of a NORDTEST method. The Moisture Buffer Value is the figure that has been developed in the project as a way to appraise the moisture buffer effect of materials, and the value is described in the paper. Also explained is a test protocol which expresses how materials should be tested for determination of their Moisture Buffer Value. Finally, the paper presents some of the results of a round robin test on various typical building materials that has been carried out in the project.
The Effect of Air Flow on Measured Heat Transport through Wall Cavity Insulation
Authors: Yarbrough David W. , Graves Ronald S.
Published: March 2009

The methods commonly used for determining the thermal resistance of insulations in wall cavities do not include the effect of air movement through the insulation. Contributions to the total building heating or cooling load include the change in enthalpy of air moving through an insulation and the heat flux through the insulation due to the imposed thermal gradient. The two effects are not independent since the air movement affects the temperature distribution in the insulation. A heat-flow-meter apparatus meeting the requirements of the Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus ASTM C 518 has been configured to allow uniform air flow across thermal test specimens. The air flow is parallel to the heat flow direction. Air is introduced into the specimen chamber of the heat-flow-meter apparatus from an external source. The heat-flow-meter with controlled air flow has been used to determine total heat-flow rates as a function of air-flow rate, air-flow direction, and temperature for commonly used wall cavity insulation.
Formulating with Rosendale Natural Cement
Authors: Edison MP
Published: March 2009

Understanding the guiding formulation principles behind the use of natural cement in the 19th and early 20th centuries allows better interpretation of the results of laboratory analyses and more accurate reproduction of historic masonry and concrete materials. This paper reviews traditional formulation practices for natural cement mortars, grouts, stuccos, concretes, and lime-washes, including ingredient selection, technical and economic criteria affecting formulation, and how the materials and formulations changed over time. Effects on performance of typical formula variations are reviewed, and potential effects on performance of modern admixtures are considered.
Managing Aldicarb Application with GPS/GIS Systems
Authors: Salyani Masoud , Miller William M. , Buchanon Sherrie , Sweeb Roy D.
Published: March 2009

Aldicarb is a soil-applied pesticide that is widely used to control certain insects, mites, and nematodes of citrus and other crops. However, due to its high toxicity and leaching potential into groundwater, many states regulate its application. In Florida, aldicarb applications require a 91.4-m buffer zone around all drinking water wells and 304.8 m around wells located in certain sandy soils. To positively control and monitor the discharge of aldicarb in field conditions, the feasibility of using several electronic control systems on the granular applicator was investigated. The project involved fabricating a prototype machine that featured both ground- and motor-driven mechanisms commonly used in commercial aldicarb applications. A ground-driven power train operated one-half of the metering wheel through an electric clutch and a pulse-width modulation (PWM) motor powered the other half. The machine was equipped with various controllers and electronic circuits. Three DGPS-based approaches were considered. The first level consisted of a DGPS antenna and a low-cost data logger. It could provide records including position information (latitude and longitude) and status of the PWM controller and electric clutch (ON/OFF of the discharge system) for monitoring purposes. The second system (mid-range cost) utilized a hand-held computer and variable-rate-application (VRA) software to input prescription maps and provide an operator real-time screen interface. With this system, it was possible to provide ON/OFF control of both discharge drives and generate as-applied maps. The third level (highest-cost) involved the use of a more sophisticated VRA controller comprising modular components and CAN bus system. It allowed detailed operator-machine interface and could input variable rate maps and output information on application rate, acreage, and total material usage. The paper elaborates on the above technology solutions and provides test results of their evaluation under simulated field conditions. Each system had certain merits and limitations but all were capable of providing useful temporal and spatial information for aldicarb application.
Mesh Tally Radiation Damage Calculations and Application to the SNS Target System
Authors: Ferguson P. D. , Gallmeier F. X. , Mansur L. K. , Wechsler M. S.
Published: March 2009

A new method for the calculation of radiation damage parameters in large geometries encompassing multiple materials using the MCNPX mesh tally has been developed. The method has been tested against previously published calculations of the displacement rate for protons and neutrons at the center of the SNS 316LN stainless steel target vessel nose. Displacement rates for neutrons, protons, and the total using the mesh tally method are shown to agree with previous work. The mesh tally method is also applied to the SNS aluminum moderator vessels and to the SNS inner reflector plug composed of aluminum, beryllium, and stainless steel. Results are given for displacement, helium, and silicon production rates.
Time-Dependent Reliability of Thermally Shocked SiC Tubes
Authors: Jadaan OM , Nemeth NN , Segall AE
Published: March 2009

In real world structural applications, applied thermal and mechanical loads vary with time such as in thermal shock, startup, shut down, and dynamic and vibrational settings. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. The objective of this paper is to demonstrate an analytical methodology capable of predicting the transient reliability of components subjected to time-dependent thermomechanical loads taking into account the change in material response with time. Weibull parameters, slow crack growth parameters, as well as the thermal and elastic material properties are allowed to vary with time. In this approach, progressive damage due to slow crack growth is accounted for. This transient reliability capability was added to the NASA CARES/Life (ceramic analysis and reliability evaluation of structures/Life) code, which was also updated to interface with commercially available finite element analysis programs executed for transient load histories. The methodology was then used to predict the transient failure probability of thermally shocked sintered alpha silicon carbide SiC tubes quenched down from 1000°C in order to demonstrate the viability of this approach and the CARES/Life code. The failure probability was computed to be 92 % while the measured failure probability was found to be up to 35 %. Sensitivity analysis showed that the computed failure probability is very sensitive to the magnitude of the axial and hoop thermoelastic stress distributions, with 10 % reduction in the stress magnitudes yielding a computed failure probability of 55 % matching the experimentally measured value.
Quantification of Constitutive Behavior of Sheet Metals Subjected to Dynamic Bulge Loading
Authors: Liu L. , Petrinic N. , Elliot B. , Ruiz C.
Published: March 2009

A newly developed method has been employed to quantify the mechanical behavior of sheet metals (both isotropic and orthotropic) subjected to dynamic bulge loading at strain rates of up to 400 s−1. Using newly developed dynamic bulge testing equipment with stereoscopic imaging, the exact shape of the bulging dome has been obtained and represented using high order polynomials before further constitutive analysis. The bulge profile functions discerned have been used to calculate the actual radius of curvature at the pole, thus replacing the spherical shape generally assumed in traditional bulge test analysis. Furthermore, the calculation of the thickness of the bulge has been improved by employing “dome volume” approaches. Effective strain and stress at the dome’s pole have been calculated considering both isotropic and orthotropic materials. The effect of gage length on the obtained values of strain and stress has been assessed.
A Method for Evaluating Fretting Wear Scars in Thin Steel Roping Wires Based on Confocal Imaging Profilometry
Authors: Urchegui M. A. , Tato W. , Gómez X.
Published: March 2009

Fretting is considered one of the most important degradation phenomena inside steel wire ropes. This phenomenon causes the formation of wear scars on individual wires, which will decrease the cross-sectional area of the rope. Hence, also the fatigue life of the rope will be reduced. The aim of this work is to describe a method for characterizing wear scars in thin steel roping wires using confocal imaging profilometry. This objective is a challenge because not only the scars are formed on curved surfaces (cylinders), but the cylinders can present helical or double-helical shape induced during the manufacturing process of the ropes. Therefore, different surface morphology measurement techniques are briefly described. A methodology to measure wear scars in steel roping wires is then presented: a confocal imaging profiler was employed and algorithms were developed to treat the data points provided by the confocal profiler and calculate the characterization parameters. In this way, the quantitative assessment of wear scars in thin steel wires can be performed.
The Development of ASTM D 4772: The Water Flow Test Method
Authors: Cary Richard T.
Published: March 2009

ASTM D 4772, “Standard Test Method for Surface Water Absorption of Terry Fabrics (Water Flow),” is a nondestructive test method for determining the effectiveness of terry fabrics and terry fabric products to remove water from various surfaces. Based on the water flow apparatus invented by employees of the former J. P. Stevens and Company, ASTM D 4772 was developed by the ASTM D 13.59 Task Group for the absorbency of woven fabrics. ASTM D 4772 was developed for use in ASTM D 5433 “Standard Performance Specification for Towel Products for Institutional and Household Use.” The single-material single-operator precision and the single-laboratory predictive validity of ASTM D 4772 were found to be good. However, the single-material interlaboratory precision of ASTM D 4772 was found to be poor.
Influence of Selected Mix Design Factors on the Thermal Behavior of Lightweight Aggregate Asphalt Mixes
Authors: Khan Ashfaq , Mrawira Donath
Published: March 2009

Lightweight aggregate (LWA) asphalt mix has been found to have lower thermal conductivity and thermal diffusivity compared to a conventional asphalt mix. Given these beneficial thermal properties, a LWA-asphalt mix can reduce frost penetration into the underlying pavement layers. It is therefore postulated that the LWA-asphalt mix can reduce damage associated with frost heave. This paper investigates the effects of binder grade and coarse aggregate content on the thermal properties of LWA-asphalt mixes. The effects of three asphalt binder grades (PG58-28, PG64-28, and PG70-28) and three aggregate gradations were investigated. The thermal conductivity was found to vary from 0.77 to 0.87 W/m°K for the LWA-asphalt mixes having bulk density in the range of 1585–1653 kg/m3 and air voids 3.5–4.5 %. Thermal diffusivity was determined to vary from 2.1 × 10−7 m2/s to 2.6 × 10−7 m2/s and a standard deviation of 0.18 × 10−7 m2/s. Specific heat capacity was found to be in the range of 1990 J/kg⋅°K to 2360 J/kg⋅°K, with a standard deviation of 130 J/kg⋅°K. Coefficients of variation for thermal conductivity, thermal diffusivity, and specific heat capacity were found to be 3.2, 6.1, and 7.6 %, respectively. These results show that the three thermal response variables vary in a very narrow range. It is concluded that the beneficial thermal properties of LWA-asphalt mixes appear to be insensitive to variation in asphalt binder grade and aggregate gradation.
Dynamic Testing of Materials with the Rotating Disk Indirect Bar-Bar Tensile Impact Apparatus
Authors: Xia Y , Wang Y
Published: March 2009

An experimental method is proposed to investigate the tensile behavior of materials at high strain rates by using a developed split Hopkinson tension bar, rotating disk indirect bar-bar tensile impact apparatus. The mechanically-filtered input tensile pulse is generated by incorporating a prefixed metal bar connected between the impact block and the input bar. The pulse amplitude is controlled by the diameter of the prefixed metal bar. The pulse duration is determined by the length of the prefixed metal bar and the velocity of the impact hammer. Dynamic properties of metallic and nonmetallic materials are presented as examples by using this developed rotating disk indirect bar-bar tensile impact apparatus.
Radiation Effects on the Metallurgical Fracture Parameters and Fracture Toughness of Pressure Vessel Steels
Authors: Wullaert RA , Ireland DR , Tetelman AS
Published: March 2009

The effect of radiation on tensile properties, notch bend properties, and fracture toughness was determined on A212B steel from the Pathfinder reactor surveillance program and on A533B steel from the U.S. AEC Heavy Section Technology program. Impact tests were performed on an instrumented Charpy machine which provided load-deflection data in addition to energy absorption data. Valid fracture toughness values were obtained from precracked Charpy specimens.

The results of the notch bend tests on the irradiated steels indicated that the radiation induced increase in the ductile-brittle transition temperature was mainly due to the large radiation induced increase in the friction stress. Radiation reduced the strain rate sensitivity of the yield stress but did not change the temperature dependence of the yield stress. The microscopic cleavage strength was essentially unaffected by irradiation. The relationships between the metallurgical fracture parameters (Cottrell-Petch) and the ductile-brittle transition temperature (DBTT) and fracture toughness (KIc) were established. These relationships were used to predict the radiation induced change in fracture toughness (both DBTT and (KIc) from a knowledge of the effect of radiation on metallurgical fracture parameters.
Neutron Irradiation Effects on Iron Containing Aluminum and Nitrogen
Authors: Igata N , Hasiguti RR , Yagi E , Nishiike U , Watanabe K
Published: March 2009

Several authors have emphasized that aluminum nitride in iron and iron alloys not only lowers the transition temperature but also suppresses the rise of the transition temperature due to irradiation. To clarify the mechanism of the effect of aluminum nitride, structural changes after irradiation and annealing are observed by means of internal friction and electron microscopy. Materials investigated are iron, containing 0.05 wt% Al and 0.01 wt% N with <1 ppm C and a few ppm 0, and iron, containing 0.02 wt% Al and 0.005 wt% N with 10 ppm C and 20 ppm 0. The materials are annealed at 750 C before irradiation and irradiated in the JRR-2 at temperatures of 60 C and up to 1.2×1019 n/cm2, E > 1 MeV. Two new peaks in internal friction are found at ∼125 C and ∼155 C after irradiation. Besides these changes a new type of precipitate is observed by electron microscopy. These precipitates are thin, doughnut shaped disks with a diameter of 0.3 μm and are considered to be complex defects of irradiation induced point defects, nitrogen, and aluminum atoms. The 125 C peak of internal friction disappears after annealing at 250 C for 30 min; the 150 C peak disappears after annealing at 150 C for 30 min or aging at room temperature for about half a year. Resolution of free nitrogen is observed, but precipitates do not disappear even after annealing at 350 C for 30 min. The precipitates suppress the formation of irradiation induced complex nitrogen defects and irradiation hardening because of the strong effect of aluminum on nitrogen atoms.
The Effect of Fast Neutron Irradiation on the Mechanical Properties of Some Quenched and Tempered Steels
Authors: Hosbons RR , Wotton BL
Published: March 2009

Specimens from seven heats of AISI 403, five heats of A542, and one heat of AISI 431 were irradiated at 300 C in pressurized water to find the effect of chemical composition on their irradiated properties. The change in ductile-brittle transition temperature ΔT after the maximum integrated fast neutron flux of 1×1020 n/cm2, E > 1 MeV, was similar for these steels. Some of the heats were also tested after an integrated flux of 6×1019 n/cm2, E > 1 MeV, and the results showed that the latter flux caused saturation of damage in AISI 403. The total impurity concentration of AISI 403 appeared to control the size of ΔT at saturation, but there was no such correlation in the other steels. Obversely, the nitrogen concentration of A542 did affect its change of transition temperature for a given flux; a titanium concentration of 0.1 weight percent increased the unirradiated transition temperature but not ΔT. AISI 431 is unsuitable for use at 300 C as it is thermally embrittled. Although the ΔT values for AISI 403 and A542 were the same, the latter had a lower initial transition temperature.
The Effect of Neutron Irradiation on the Mechanical Properties of Zirconium Alloy Fuel Cladding in Uniaxial and Biaxial Tests
Authors: Hardy DG
Published: March 2009

Short-time axial tension, transverse ring tension, and biaxial closed end burst tests were conducted on sections of fuel cladding from 17 different batches and heat treatments of Zircaloy 2, Zircaloy 4, and Zr-2.5Cb alloy. Specimens were irradiated at 2 to 3×1020 n/cm2, E > × MeV, at temperatures of 125 to 250 C and tested at temperatures of 20 and 300 C.

The level of residual cold work was found to have the greatest effect on the mechanical properties of the Zircaloys prior to irradiation, and, although irradiation altered the general level of each property, the effect of cold work was preserved after irradiation for all properties except the uniform elongation. Very low values of uniform elongation (< 1 percent) were obtained in the burst test after irradiation at all levels of cold work. In the instances where the texture and grain size influenced the properties, the effect was also preserved after irradiation. For the Zircaloys, the increment in the strength properties due to irradiation was constant at this fluence, independent of cold work, texture, and grain size. The decrements in the uniform and total elongations due to irradiation decreased with increasing cold work. The irradiation hardening of the Zr-2.5Cb alloy was greater than that experienced by the Zircaloys.

Beta heat-treated Zircaloy had higher strength and lower ductility than alpha annealed material in the tension test. Grain size was found to have a much more significant effect on the strength and ductility in the burst and ring tests than in the axial tension test.
Metallurgical Properties of Cold-Worked Zircaloy 2 Pressure Tubes Irradiated Under CANDU-PHW Power Reactor Conditions
Authors: Langford WJ
Published: March 2009

The performance of cold-worked Zircaloy 2 reactor pressure tubes has been assessed by destructive tests of tubes irradiated under CANDU-PHW power reactor conditions of temperature (240 to 280 C), stress (10,500 to 17,200 psi), and neutron irradiation. Reactor service increases biaxial burst strength, accompanied by a change in deformation mode that leads to reduced ductility after irradiation. Crack tolerance of the tubing is virtually unaffected by reactor service, and the critical crack length exceeds 3 in. (75 mm) at 16,000 psi (11.3 kg/mm2) hoop stress and 300 C.

Uniaxial tension tests indicate that operating stress reduces the transverse tensile strength of unirradiated tubing. Irradiation strengthening appears to be direction dependent, suggesting a possible influence of operating stress on the distribution of irradiation damage. Transmission electron microscopy shows the damage to be in the form of discrete dislocation loops.

Oxidation rate in water is enhanced by neutron irradiation but is acceptably low, as is hydrogen/deuterium pickup. Diameter measurements support the evidence from in-pile creep investigations that creep rate partly depends on fast neutron flux.
The Temperature and Neutron Dose Dependence of Irradiation Growth in Zircaloy 2
Authors: Harbottle JE
Published: March 2009

Irradiation growth due to fast neutron bombardment has been measured in textured Zircaloy 2 as a function of neutron dose (ϕt) and irradiation temperature. The growth strain ε obeys a relationship ε∝ (ϕt)n over a temperature range -196 to 280 C and for doses up to 1021 n/cm2. For irradiation temperatures up to 80 C, n = 0.4; but at 280 C, n = 0.7. The temperature dependence of irradiation growth in Zircaloy 2 is small, and in the temperature and dose ranges considered the growth strains do not differ by more than a factor of four. The growth rate G∝d ε/d (ϕt) is initially large at low doses but approaches 1 at high doses (∼;1021 n/cm2).
The Mechanism and Kinetics of Void Growth During Neutron Irradiation
Authors: Bullough R , Perrin RC
Published: March 2009

A theoretical model is presented that is particularly appropriate for a study of void growth kinetics at high neutron doses. These kinetics are presented for peak swelling temperatures where recombination effects can be neglected; their dependence on dislocation density, void density, and dose rate is discussed.
Neutron Dosimetry for Fast Reactor Applications
Authors: McElroy WN , Dahl RE
Published: March 2009

The status of fast reactor dosimetry is reviewed in terms of the results of recent studies in fast test reactors. Fast reactor dosimetry must provide proper spectral, flux, and fluence information for material and fuel irradiation effects programs and surveillance studies. In this review consideration is given to (1) monitor materials in current use and information needed in the data reduction of reaction product measurements to neutron interaction rates, (2) neutron flux-spectral definition from multiple foil interaction rates and comparison with results based on other methods of analysis, and (3) application of the flux-spectral data to determination of flux levels and fluences. These dosimetry techniques are applied to determine flux spectra and fluence for material irradiation programs. Such information is needed in the determination of damage functions, which relate the damage producing effectiveness of neutrons to their energy. These damage functions permit correlation of irradiation effects data in different thermal and fast reactor irradiation facilities and therefore provide a basis for setting dosimetry accuracy requirements.
Neutron Fluence Limit Determinations for Some Fast Flux Test Facility Components
Authors: Moen RA , Tobin JC , Thomas KC
Published: March 2009

This paper describes the analytical procedures that have been developed at Battelle-Northwest Laboratory (BNWL) and Westinghouse Advanced Reactors Division (ARD) to determine neutron fluence limits for certain components of the Fast Flux Test Facility (FFTF), namely the core barrel, core support structure, and the reactor vessel.
Effect of Fast Neutron Irradiation on the Creep Rupture Properties of Type 304 Stainless Steel at 600 C
Authors: Bloom EE , Stiegler J
Published: March 2009

The creep rupture properties of Type 304 stainless steel have been determined at 600 C after irradiation at temperatures in the range from 370 to 600 C to fast neutron fluences of 1×1021 to 6.7×1022 n/cm2, E >0.1 MeV. The microstructures were characterized by electron microscopy. Irradiation at 370 to 470 C caused a decrease in ductility and rupture life which became larger with increasing fast neutron fluence. The irradiated specimens fractured along the grain boundaries with no evidence of deformation within the matrix. A specimen irradiated at 410 C to 6.7×1022 n/cm2 ruptured in 0.5 h with 0.1 percent elongation, as compared to a rupture life of 185 h and elongation of 19.7 percent for the unirradiated material tested at the same stress. Specimens irradiated at 600 C to fluences from 2.5 to 3.5 ×1022 n/cm2 exhibited decreased ductilities and creep rates and essentially the same rupture lives as unirradiated specimens.

The increased tendency for grain boundary fracture, and thus reduced ductility and rupture life, appears to result from the effects of the irradiation produced voids and dislocations upon deformation processes, which effects would be inoperative in an unirradiated specimen. The voids and dislocations prevent dislocation motion within the matrix. Regions along grain boundaries are denuded of these defects and grain boundary sliding occurs, leading to stress concentrations and the initiation of grain boundary cracks. The presence of helium at the boundaries may increase the rate of crack propagation.
Influence of Neutron Irradiation on the Creep Rupture Properties of a 16Cr-13Ni Steel
Authors: Ehrlich K , Böhm H , Wassilew C
Published: March 2009

The influence of neutron irradiation (up to 1.1 x1022 n/cm2, E>0.1 MeV) on the creep rupture properties of a Cb stabilized 16Cr-13Ni steel was studied in this paper. Different heat treatments and cold work conditions and several irradiation temperatures were investigated.

Low-temperature irradiation causes an increase in time to rupture at 650 and 750 C, whereas creep rate is reduced by more than a factor of ten. The creep ductility decreased to less than 1 percent. High-temperature irradiation does not cause a substantial change in rupture time at 650 C for the aged condition and the 50 percent cold work and 50 percent cold work+1 h 850 C conditions.

The rupture life of specimens which were cold-worked 10 percent is strongly decreased by irradiation. Only slight changes in creep rate could be observed after high-temperature irradiation. Electron microscopy investigations indicate that the increase in rupture life and reduction in creep rate after low-temperature irradiation is due to a large number of dislocation loops. In the specimens irradiated at 650 C and above only He bubbles could be detected.
Correlation Between the Mechanical Properties and Microstructure of Irradiated Iron and Low-Carbon Steel
Authors: Stefanović VM , Milašin NLj
Published: March 2009

The radiation hardening of iron and low-carbon steel was studied on the basis of transmission electron microscopy and tension test data. No visible defects were observed in the iron specimens after irradiation to 3.5×1019 n/cm2, E>1 MeV, at 35 C, as well as after postirradiation annealing at 150 C. Marked microstructural changes occurred in steel irradiated to 2.5×1018 n/cm2 both at 320 C and 450 C. In the former case a 5.1×109 cm-2 increase in dislocation density was found, while in the latter the presence of small dislocation loops of average diameter 200 Å and density 2.4×1014 cm-3 was observed.

The approximative theoretical values of yield stress increment were calculated using the models for hardening by small dislocation loops and by a dislocation forest and were compared with the experimental values of the yield stress increment. A satisfactory agreement was obtained.
Irradiation Effects at Cryogenic Temperature on Tensile Properties of Titanium and Titanium-Base Alloys
Authors: Younger CL , Haley FA
Published: March 2009

Significant increases in tensile strength and slight decreases in ductility occur when titanium and titanium-base alloys are irradiated at 17 K to 1 to 10×1017 fast neutrons per square centimeter. The magnitude of the irradiation effect appears to depend on total alloy content and, over the fluence range investigated, does not reveal a significant dependence on impurity content or initial heat treat condition. These results were obtained using commercially pure titanium, Ti-5Al-2.5Sn (normal impurity and extralow impurity contents), Ti-6Al-4V (annealed and age hardened conditions), and Ti-8Al-1Mo-1V alloys. Test specimens were exposed to irradiations at 17 K and then tension tested at 17 K without interevning warmup using test loops specially designed and fabricated for cryogenic irradiation testing. Additional results, using commercially pure titanium, show recovery of about 50 percent of the irradiation induced increase in yield strength following heat treatment at 178 K. For the ultimate strength, 50 percent recovery occurred following heat treatment at 78 K.
Environmentally Controlled Cavitation Test (Improvements in a Cavitating Film Erosion Test)
Authors: Hobbs JM , Rachman D
Published: March 2009

Early attempts to produce cavitation erosion on a stationary specimen close to a vibrating probe showed promise as a means of testing weak materials and coatings. However, the geometry affected the damage rate, the condition of the cavitating liquid was not accurately known, and the temperature in the cavitation zone rose appreciably. An improved version of this test has been devised at the University of Strathclyde, Glasgow, and subsequently further developed at the National Engineering Laboratory, East Kilbride.

The specimen is mounted a small distance from the vibrating probe, and liquid is fed continuously through a central hole in the stationary specimen. With water the temperature rise could be kept easily below 2 C. In oil, although the temperature rise was considerably higher (10 C) it was under complete control and depended mainly on the flow rate and specimen separation.

The erosion pattern obtained on the stationary specimen was well distributed and fairly uniform. The rate of erosion reach an early maximum value and then decreased with time. It decreased as the separation was increased. Optimum test conditions were obtained with 0.5 mm (0.020 in.) separation from a 20 kHz vibrator having a peak-to-peak amplitude of 50μm (0.002 in.). The specimen and vibrating probe were both 16 mm (5/8 in.) diameter. Effects of probe amplitude, test liquid flow rate, temperature, and static pressure were examined.

This technique has been used with considerable success for the evaluation of white-metal layers in lubricating oils, fiber-reinforced epoxy resins in water, and a range of typical engineering alloys.
Cavitation Damage Mechanism and Its Correlation to Physical Properties of Material
Authors: Hirotsu M
Published: March 2009

Several test surface configurations were proposed by which better reproducibilities of experimental results were achieved. There were no mechanical difficulties in machining and polishing test specimens.

Cavitation phenomena on the surface of a specimen were photographed with a special camera arrangement at adequate intervals within a cycle. These phenomena have been classified into three processes: generating, growing, and collasping. Each regime was studied closely by the aid of photographs.

Long exposure time tests, with the use of the proposed test specimens, showed mean depth penetration rate (MDPR) curves somewhat different from those previously reported. They reached the maximum MDPR in a relatively short time and decreased.

Observations of the damaged surfaces were made by means of an optical roughness meter and an ordinary microscope. The curves of maximum pit depth versus time showed a close relation to the MDPR curves.

To find a correlation between damage and physical properties of material, maximum MDPR and ultimate resilience (UR) were employed. In a very rough approximation, the correlation was (maxMDPR×area)×(UR)≑constant

The advantage of taking the maximum MDPR as a reference value was shown clearly in the results of stationary test specimen experiments. Within the limits of uniform damage patterns, the following simple relation was found. maxMDPR≑Ke-βx where x is a separation distance and β is a constant having no relation with the nature of material tested. It is assumed that K is the most characteristic value of maximum MDPR, since it is a hypothetical value when there is no vibratory motion to induce cavitation.
Cavitation Erosion of a Ship Model Propeller
Authors: van der Meulen JHJ
Published: March 2009

A four-bladed propeller model has been tested in a water tunnel with a flow regulator. Cavitation erosion of the aluminum alloy blades was caused by simulating the wake pattern behind a single screw ship in the test section of the tunnel. The relationship between the rate of weight loss and the time of exposure to cavitation was measured for each blade individually. Comparative tests, using the same material, have been carried out in a rotating disk apparatus and a magnetostriction oscillator. The erosion rates of the propeller model and of the specimens tested in the rotating disk apparatus show a similar dependence on time during the incubation, acceleration, and deceleration period. A steady-state period does not occur. The erosion rates of the specimens tested in the magnetostriction oscillator show a considerably different dependence on time. The mean erosion intensity of the test devices is 2.5 to 3 times larger than with the propeller model, based on the actual time of exposure to cavitation.
Erosion Rate-Velocity Dependence for Materials at Supersonic Speeds
Authors: Schmitt GF
Published: March 2009

A comprehensive investigation of plastic, elastomeric, ceramic, glass, metallic, and composite materials for short exposure time—rain erosion resistance at velocities of Mach 1.5, 2.0, 2.5, 3.0, and 4.0 has been accomplished.

Wedge-shaped holders capable of exposing multiple materials specimens at five different impact angles were designed, fabricated, calibrated, and successfully employed for 65 supersonic firings on the rocket sled track at Holloman Air Force Base, N. Mex.

Droplet breakup effects on the wedge because of shock-wave-droplet interactions have been analyzed and found to influence a portion of the data. Quantitative data in the form of weight loss per unit area and mean depth of penetration rate (MDPR) were determined for the various materials, and an equation for relating the erosion rate (MDPR) with the normal component of the velocity (V sinθ) was developed as follows: MDPRsinθ=K(Vsinθ)α Values of K and α have been determined for all of the materials.

The relationship of erosion rate-velocity dependence for numerous materials at powers of five or greater for the velocity exponent has been confirmed at velocities up to three times as great as previously conducted.

The values for the velocity exponent (α) have been determined as 6 to 10 for bulk ceramics, 5 to 7 for bulk plastics and fiber-reinforced plastic composites, 6 to 8 for glasses, and 7 for aluminum indicating a very strong erosion rate-velocity dependence at speeds up to Mach 4.0.