bluuebunny/crossref_metadata_2025 huggingface dataset:
Anticoagulation in the Treatment of Established Venous Thromboembolism in Patients With Cancer
Authors: Lee Agnes Y.Y.
Published: September 2009

Cancer-associated thrombosis is a frequent and costly complication in patients with cancer. Significant morbidity and mortality not only result from thrombotic events, but may also occur as a result of the therapeutic interventions. The established treatment for cancer-associated thrombosis is anticoagulant therapy. Of the few options available, low molecular weight heparin (LMWH) is the preferred agent because of its efficacy, safety, and convenience. Alternatives to LMWH have undesirable limitations and have demonstrated poorer efficacy and safety in the oncology population. Treatment of recurrent thrombosis, patients with concurrent bleeding issues, role of vena cava filter insertion, and duration of therapy are all areas in need of urgent research. Treatment of cancer-associated thrombosis remains a challenging task and is limited by the paucity of evidence-based data. Research is urgently needed to advance current practice and improve patient care.
Genetic Link Between Cancer and Thrombosis
Authors: Boccaccio Carla , Comoglio Paolo M.
Published: September 2009

From the beginning of their lives, cancer cells exert a procoagulant activity in their microenvironment, which can extend systemically and become clinically evident as Trousseau's syndrome, the well-known association between tumor and thrombosis. It is becoming clear that the genetic mechanisms responsible for neoplastic transformation (activation of oncogenes such as RAS or MET, and inactivation of tumor suppressor genes such as p53 or PTEN) directly induce the expression of genes controlling hemostasis. Activation of blood coagulation results in a selective advantage for cancer cells, as fibrin provides a scaffold for anchorage and invasion, and coagulation proteins induce receptor-mediated intracellular signals promoting invasive growth. Targeting the tumor procoagulant activity can fight not only a dangerous tumor adverse effect, but also the core mechanisms of cancer onset and progression.
Prevention of Venous Thromboembolism in the Cancer Surgical Patient
Authors: Kakkar Ajay K.
Published: September 2009

Venous thromboembolism is a common complication in patients with malignant disease. One of the environments in which patients can present with symptomatic thromboembolic disease is in the postoperative period. Operation in the patient with cancer increases the risk of thromboembolic complications some two to three fold. A variety of methods have been evaluated for the prevention of thromboembolic disease in cancer surgical patients. The most extensively investigated are the pharmacologic methods, including low-dose unfractionated heparin and low molecular weight heparin. These agents are recommended for the prevention of thromboembolic disease during hospital stay. For selected high-risk populations, extended thromboprophylaxis into the postdischarge period is also recommended.
Toxoplasma gondiiinfection confers resistance against BimS-induced apoptosis by preventing the activation and mitochondrial targeting of pro-apoptotic Bax
Authors: Hippe Diana , Weber Arnim , Zhou Liying , Chang Donald C. , Häcker Georg , Lüder Carsten G. K.
Published: September 2009

In order to accomplish their life style, intracellular pathogens, including the apicomplexan Toxoplasma gondii, subvert the innate apoptotic response of infected host cells. However, the precise mechanisms of parasite interference with the mitochondrial apoptotic pathway remain unknown. Here, we used the conditional expression of the BH3-only protein BimS to pinpoint the interaction of T. gondii with the intrinsic pathway of apoptosis. Infection of epithelial cells with T. gondii dose-dependently abrogated BimS-triggered release of cytochrome c from host-cell mitochondria into the cytosol, induction of activity of caspases 3, 7 and 9, and chromatin condensation. Furthermore, inhibition of apoptosis in parasite-infected lymphocytes counteracted death of Toxoplasma-infected host cells. Although total cellular levels and mitochondrial targeting of BimS was not altered by the infection, the activation of pro-apoptotic effector proteins Bax and Bak was strongly impaired. Inhibition of Bax and Bak activation by T. gondii was seen with regard to their conformational changes, the cytosol-to-mitochondria targeting and the oligomerization of Bax but not their cellular protein levels. Blockade of Bax and Bak activation was not mediated by the upregulation of anti-apoptotic Bcl-2-like proteins following infection. Further, the BH3-mimetic ABT-737 failed to overcome the Toxoplasma-imposed inhibition of BimS-triggered apoptosis. These results indicate that T. gondii targets activation of pro-apoptotic Bax and Bak to inhibit the apoptogenic function of mitochondria and to increase host-cell viability.
A flow field study of the interaction between a centrifugal compressor impeller and two different volutes
Authors: Dai Y , Engeda A , Cave M , Di Liberti J-L
Published: September 2009

The interaction between an impeller with one large and one small overhung volute was investigated by both computational fluid dynamics simulation and experimental methods. The large volute was mainly generated by increasing the small volute axial length. The computational model, with k—∊ turbulence model and wall function, has been used to predict the internal flow of both volutes. The effect of volute tongue on the flow in the impeller was analysed at off-design conditions. The flow structure in the volutes was also investigated in detail.

The performance test of the two configurations was carried out in the aero test facility at Solar Turbines Inc. A good agreement between experimental data and numerical simulation results was found on both the whole compressor stage performance and the impeller performance. The largest deviation is close to 10 per cent for the compressor stage performance prediction at high mass flowrate only.
Variable stress ratio in cumulative fatigue damage: Experiments and comparison of three models
Authors: Rambabu D V , Ranganath V R , Ramamurty U , Chatterjee A
Published: September 2009

We use the results of new fatigue experiments conducted with variable load levels as well as variable stress ratios to critically assess three (two old and one relatively new) cumulative fatigue damage models. Such models are usually tested using multiple blocks of periodic loading with differing amplitudes. However, available data pertain to zero-mean loading, and do not investigate the role of the variable stress ratio ( Smin/ Smax). Here, we present experimental results for variable stress ratios. Two specimen geometries and two materials (Al 2014 and Al 2024) are tested. Manson's double linear damage rule (DLDR) gives the highest accuracy in predicting the experimental outcome, even in the presence of variable stress ratios, whereas predictions of the newer model (‘a constructive empirical theory for metal fatigue under block cyclic loading’, Proc. R. Soc. A, 2008, 464, 1161–1179) are slightly inferior. The widely used Miner's rule is least accurate in terms of prediction. The merits and drawbacks of these models, in light of the experimental results, are as follows. The DLDR, though accurate, has minor scientific inconsistencies and no clear generalization. The constructive model has possible generalizability and more appealing scientific consistency, but presently has poorer accuracy. Miner's rule, though least accurate, lies within the constructive approach for special parameter values. The DLDR can guide the new (constructive) approach through new parameter fitting criteria.
Computational fluid dynamics and virtual aeroengine modelling
Authors: Chew J W , Hills N J
Published: September 2009

Use of large-scale computational fluid dynamics (CFD) models in aeroengine design has grown rapidly in recent years as parallel computing hardware has become available. This has reached the point where research aimed at the development of CFD-based ‘virtual engine test cells’ is underway, with considerable debate of the subject within the industrial and research communities. The present article considers and illustrates the state-of-the art and prospects for advances in this field. Limitations to CFD model accuracy, the need for aero-thermo-mechanical analysis through an engine flight cycle, coupling of numerical solutions for solid and fluid domains, and timescales for capability development are considered. While the fidelity of large-scale CFD models will remain limited by turbulence modelling and other issues for the foreseeable future, it is clear that use of multi-scale, multi-physics modelling in engine design will expand considerably. Development of user-friendly, versatile, efficient programs and systems for use in a massively parallel computing environment is considered a key issue.
Adaptive gravity compensation of decoupled parallel and serial manipulators using a passive hydraulic transmission
Authors: Lauzier N , Gosselin C , Laliberté T , Tremblay P
Published: September 2009

This article addresses the gravity compensation of decoupled or partially decoupled parallel and serial manipulators. The proposed technique applies to manipulators in which the vertical motion is decoupled from other Cartesian degrees of freedom (DOFs). In the latter situation, only one DOF needs to be gravity compensated in order to eliminate actuator torques due to the weight of the moving parts. First, a passive hydraulic transmission consisting of two cylinders connected by hoses is introduced in order to perform gravity compensation using a remote counterweight (CW) affecting only the inertia of the equilibrated DOF. A complete system is then shown using a set of CWs, cylinders, and valves allowing to adapt rapidly and effectively to a variety of payloads. Finally, two experimental implementations using, respectively, hydraulic and pneumatic cylinders filled with water are presented and the practical limitations of the approach are discussed.
A robust structural design method using the Kriging model to define the probability of design success
Authors: Lee K-H
Published: September 2009

In this study, a robust optimization method is proposed by introducing the Kriging approximation model and defining the probability of design-success. A key problem in robust optimization is that the mean and the variation of a response cannot be calculated easily. This research presents an implementation of the approximate statistical moment method based on the Kriging metamodel. Furthermore, the statistics using the second-order statistical approximation method are adopted to avoid the local robust optimum. Thus, the probability of design-success, which is defined as the probability of satisfying the imposed design requirements, is represented as a function of approximate mean and variance. The formulation for the robust optimization can be defined as the probability of design-success of each response. The mathematical problem and the design problems of a two-bar structure and microgyroscope are investigated for the validation of the proposed method.
Catalytic Mannich-Type Reactions of Sulfonylimidates
Authors: Matsubara Ryosuke , Berthiol Florian , Nguyen Huy V , Kobayashi Shu
Published: September 2009

A novel nucleophile, sulfonylimidate, has been successfully employed in Mannich-type reactions. Due to electron-withdrawing property of sulfonyl group of sulfonylimidate, the acidity of α-proton is enhanced so that sulfonylimidate bearing no activating functional group at α-position is deprotonated by relatively weak base. DBU-catalyzed reactions of sulfonylimidates with protected imines in DMF provided the adducts in high yields with high anti selectivity. This reaction represents a wide substrate scope and a high catalytic turnover. A thorough kinetic study revealed that rate-determining step is most likely deprotonation step in case of Ts-imidate. Alkali earth metal alkoxide and its HMDS salt also catalyze Mannich-type reactions of sulfonylimidates. The reactions catalyzed by Mg(OtBu)2 in DMF provided the adducts with high anti selectivity, while those catalyzed by [Sr(HMDS)2]2 gave syn selectivity. The asymmetric variant of Mannich-type reaction of sulfonylimidate was also achieved. Several transformations of sulfonylimidates to other functional groups were also demonstrated. Finally, direct-type catalytic formation of β-amino acid ester from aldehyde and sulfonylimidate was achieved via in situ formation of sulfonylimine and DBU-assisted hydrolysis of sulfonylimidate.
Cyclopropanation Reactions of Halomethyllithium Carbenoids: A Computational Study of the Effects of Aggregation and Solvation
Authors: Pratt Lawrence M , Trần Phương Thảo Thị , Nguỹên Ngân Van , Ramachandran Bala
Published: September 2009

Computational results are presented to support experimental evidence that cyclopropanation reactions of halomethyllithium carbenoids with alkenes occur through the concerted (methylene transfer) pathway rather than the alternate stepwise (carbometalation) pathway in non-polar and polar (THF, ε = 7.85) media. These results complement and confirm the recent findings of Ke, Zhao, and Phillips (KZP) [J. Org. Chem.2007, 72, 848] for ethylene in nonpolar and moderately polar (DME, ε = 4.34) solvents. We also studied carbenoid reactions with 2,3-dimethyl-2-butene. The explanation for the preference for the concerted pathway is provided by detailed examination of the reaction pathways of aggregated carbenoid species, which are the dominant reactive species in both polar and nonpolar solvents. The details of the syn and anti eliminations of lithium halide from the intermediate formed in the two-step mechanism with ethylene are also studied for the first time. Two stable dimeric structures were identified for the carbenoids and both have been studied. By explicit coordination of the monomeric and dimeric organolithium species to THF ligands, we also find that a clear preference for the concerted pathway is shown by both monomers and dimers in polar solvents, and solvent steric factors are dominant in determining the relative stabilities of the aggregates of the carbenoid species in THF solution.
Color Tuning Mechanism of Human Red, Green, and Blue Cone Pigments: SAC-CI Theoretical Study
Authors: Fujimoto Kazuhiro , Hasegawa Jun-ya , Nakatsuji Hiroshi
Published: September 2009

Human red (HR), green (HG), and blue (HB) cone pigments are responsible for human color vision, and their photoabsorption wavelengths spread uniquely over the three primary colors. These pigments, however, include only one common chromophore, retinal. Here, we report physical basis of the color tuning in human vision on the basis of SAC-CI calculations for excited states of the cone pigments. The dominant origin of the red–green–blue distinction lies in differences in electrostatic interactions between retinal and its surrounding proteins. Structural distortion effect of the retinal chromophore is important in human blue pigment. Detailed analysis on individual roles of amino acids within these proteins has clarified elaborate mechanisms of the color tuning, in accordance with previous mutagenesis experiments. Furthermore, the color tuning is regulated by amino acids at specific positions in the proteins, suggesting some genetic origins for the color tuning.
Reaction Paths toward Isocyanate Adducts
Authors: Hatanaka Masashi
Published: September 2009

Addition reactions of isocyanates were theoretically investigated. The simplest model compounds for urethanes, thiourethanes, and ureas were analyzed to find bimolecular reaction profiles. The transition states suggested intramolecular hydrogen-transfer processes, in which highly acidic hydrogens hopped.
One-Pot Two-Step Solvent-Free Rapid and Clean Synthesis of 2-(Substituted Amino)pyrimidines by Microwave Irradiation
Authors: Goswami Shyamaprosad , Hazra Anita , Jana Subrata
Published: September 2009

A series of diversely 2-(substituted amino)pyrimidines (along with ring substitution) has been synthesized under solvent- and catalyst-free microwave conditions from substituted guanidines and β-diketones. The substituted guanidines are synthesized from (S)-methylisothiourea sulfate and different amines (various alkyl, aryl, or heterocyclic and also chiral amines) under microwave irradiation. These two-step reactions are performed in one-pot without isolating any intermediate. This protocol has been successfully applied for the synthesis of bisaminopyrimidines and 2-substituted aminopyrimidines containing chiral moiety where chirality remains undisturbed.
Synthesis of Derivatives of Phenanthrene and Helicene by Improved Procedures of Photocyclization of Stilbenes
Authors: Talele Harish R , Gohil Monik J , Bedekar Ashutosh V
Published: September 2009

An improved method has been developed for photocyclization of stilbene to construct phenanthrenes and benzo[c]phenanthrenes. This reaction is promoted by iodine while tetrahydrofuran is used as an efficient and inexpensive scavenger of hydroiodic acid produced during the photocyclization sequence. In another process, cyclohexene is used as a reagent for dehydrogenation step in place of THF–I2.
Lean NOx Reduction by Hydrogen over Pt-Supported Rare Earth Oxide Catalysts and Their In Situ DRIFTs Study
Authors: Itoh Masahiro , Motoki Koji , Saito Makoto , Iwamoto Jun , Machida Ken-ichi
Published: September 2009

The Pt-supported rare earth oxide (CeO2, Pr6O11, Eu2O3, and Gd2O3) catalysts were prepared and their selective catalytic reduction (SCR) characteristics for NOx using hydrogen were investigated under 10 vol % excess oxygen conditions. Among them, only the Pt/CeO2 catalyst provided good NO conversion (ca. 80%) with ca. 40% N2 selectivity. Other catalysts hardly showed NOx reduction activity due to the high solid basicity of supporting materials. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) measurements for the Pt/CeO2 catalyst were performed to obtain the specific adsorption bands assigned to NO3− species, indicating that NOx reduction proceeds via formation of such nitrate.
The metric‐frequency measure of similarity for ill‐structured data sets, with an application to family therapy
Authors: Sales Célia M. D. , Wakker Peter P.
Published: September 2009

Similarity measures have been studied extensively in many domains, but usually with well‐structured data sets. In many psychological applications, however, such data sets are not available. It often cannot even be predicted how many items will be observed, or what exactly they will entail. This paper introduces a similarity measure, called the metric‐frequency (MF) measure, that can be applied to such data sets. If it is not known beforehand how many items will be observed, then the number of items actually observed in itself carries information. A typical feature of the MF is that it incorporates such information. The primary purpose of our measure is that it should be pragmatic, widely applicable, and tractable, even if data are complex. The MF generalizes Tversky's set‐theoretic measure of similarity to cases where items may be present or absent and at the same time can be numerical as with Shepard's metric measure, but need not be so. As an illustration, we apply the MF to family therapy where it cannot be predicted what issues the clients will raise in therapy sessions. The MF is flexible enough to be applicable to idiographic data.
The Therapist's Imagination of Self in Relation to Clients: Beginning Ideas on the Flexibility of Empathic Imagination
Authors: Flaskas Carmel
Published: September 2009

The therapist's capacity to imagine is one specific part of the endeavour of empathy which lies at the heart of the processes of the therapeutic relationship. This article offers beginning ideas about the significance of therapist's imagination of self in relation to her/his clients in the task of trying to understand their experience. In seeking to ‘understand’ the experience of others, the therapist is able to move between an imagination of sameness/identification with the client/s, and an imagination of difference/‘foreignness’. The family therapy orientation of curiosity and ‘not‐knowing’ relies on the imagination of self as different to our clients; more traditional understandings of empathic connection rely more heavily on the imagination of sameness/identification with clients. This article argues that flexibility in the therapist's use of self in moving between these positions allows an expanded capacity for therapeutic connectedness. These ideas have special valence in the practice territories of impasse and intercultural therapy.
Key Systemic Ideas as Seen Through the Eyes of First‐Year Trainees
Authors: Garven Roxanne , White Helen
Published: September 2009

This article offers an introduction to key systemic ideas as seen through the eyes of first‐year trainees in a postgraduate systemic therapy course. Our aim is to present these ideas in user‐friendly, accessible language, with examples to illustrate their use. The article is organised around three main themes: how a family system gets organised; how systemic work helps to effect change in families; and how a systemic therapist creates a context for change. Ideas covered include circular patterns, processes and questions, feedback loops, the importance of context, the interdependence of meaning and action, taking a meta‐perspective, systemic hypothesising, neutrality, curiosity, second‐order change, use of language and the position of the therapist. The article may be of particular interest to those who are new to systemic ideas, as well as for those involved in providing training in systemic practice.
Buyer Monitoring: A Means to Insure Personalized Service
Authors: Kwortnik Robert J. , Lynn W. Michael , Ross William T.
Published: September 2009

Marketing scholars have proposed that service employees play a primary role in delivering service quality. However, the question of how to motivate service employees to enhance service production has received little research attention. The authors address this gap by advocating a control mechanism first discussed in the economics literature—buyer monitoring. The authors focus on a pervasive form of buyer monitoring, voluntary tipping, and examine the effectiveness of this control mechanism as a means for improving service in two contexts: leisure cruises and restaurant dining. Despite a substantial interdisciplinary literature reporting a weak relationship between customers' perceptions of service and their tipping behavior, the results show that a policy of voluntary tipping has positive effects on the motivation and behavior of service workers and on customers' perceptions of the service those workers provide. These findings call attention to buyer monitoring as both a topic for academic research and a practical mechanism for motivating service employees. The findings also call into question trends away from tipping in service contexts, such as the cruise industry, and suggest that many service businesses for which tipping is not viable can benefit from alternative forms of buyer monitoring.
When Should Original Equipment Manufacturers Use Branded Component Contracts with Suppliers?
Authors: Ghosh Mrinal , John George
Published: September 2009

Branded components are becoming increasingly popular in industrial markets; yet extant research provides limited understanding of the use of such arrangements in the real world. The authors use the governance lens of transaction cost economics to propose that leveraging the vendor's brand reputation and safeguarding the vendor's customization investments are key motivators for choosing branded component contracts. Data on 191 contracts from three engineering-intensive industry sectors provide support to the authors' hypotheses. The authors find that firms are more likely to choose branded component contracts when the supplier's brand name adds significant differentiation (leveraging) and when the component supplier has made significant component customization investments (safeguarding). This safeguarding motivation is relevant even to suppliers with modest brand reputation. The authors also investigate the normative consequences of these contracting decisions and find significant adverse outcomes from choosing the “wrong” contract form. Furthermore, they find that these outcomes are asymmetric in nature. In particular, choosing a “white box” contract when the theory argues for a branded component contract leads to more adverse outcomes than choosing a branded component contract when the theory predicts a “white box” contract. Finally, the authors draw key conclusions for theory and managerial practice.
Modeling Global Spillover of New Product Takeoff
Authors: Van Everdingen Yvonne , Fok Dennis , Stremersch Stefan
Published: September 2009

This article examines the global spillover of foreign product introductions and takeoffs on a focal country's time to takeoff, using a novel data set of penetration data for eight high-tech products across 55 countries. It shows how foreign clout, the susceptibility to foreign influences, and intercountry distances affect global spillover patterns. The authors find that foreign takeoffs, but not foreign introductions, accelerate a focal country's time to takeoff. The larger the country, the higher its economic wealth, and the more it exports, the more clout it has in the global spillover process. In contrast, the poorer the country, the more tourists it receives, and the higher its population density, the more susceptible it is to global spillover effects. Cross-country spillover effects are stronger the closer the countries are to one another, both geographically and economically, but not necessarily in terms of culture. The model the authors develop also quantifies the spillover between each country pair, allowing it to be asymmetric.
Sales Effects of Attention to Feature Advertisements: A Bayesian Mediation Analysis
Authors: Zhang Jie , Wedel Michel , Pieters Rik
Published: September 2009

There is much evidence that the presence of a feature advertisement can increase the sales and market share of the featured product. However, little is known about how feature ad characteristics (e.g., size, color, and location of the advertisement) affect the sales outcomes and how the effects take place. Prior research has predicted that feature advertisements lead to behavioral outcomes through their effect on consumers' attention. Building on this idea, the authors propose a Bayesian statistical model to study how feature ad characteristics affect sales of the featured products and the mediating role of attention in these relationships. They use data from eye-tracking tests of feature advertisements, aggregated and matched with sales data at the level of the feature advertisement. Their approach accounts for endogeneity in the key variables involved and overcomes limitations of standard mediation analyses. They show that the gaze duration on a feature advertisement affects sales of the featured product beyond the mere presence of the advertisement and that a standard mediation analysis that does not accommodate endogeneity produces biased estimates of the effects of feature ad characteristics on sales. Their proposed methodology is widely applicable to mediation analyses. The findings imply that attention data collected in lab tests can help marketers compare the relative sales outcomes of different feature ad designs and improve the effectiveness and efficiency of feature adverting decisions.
Specifying Price Judgments with Range–Frequency Theory in Models of Brand Choice
Authors: Niedrich Ronald W. , Weathers Danny , Hill R. Carter , Bell David R.
Published: September 2009

To construct a price judgment, consumers compare a focal price with one or more reference prices. However, reference price operationalizations in the brand choice literature use single-point summary measures that cannot account for several distributional effects. To account for effects beyond the first moment of the reference price distribution, the authors specify price judgments in models of brand choice in accordance with range–frequency theory. The findings indicate that range–frequency price judgments provide a more complete specification of reference price effects and become more important with an increase in the second and third moments of a reference price distribution. The data also indicate that range effects are stronger for coupon users and frequency effects are stronger for consumers exposed to a trend of prices. The results have several implications for choice modeling, pricing theory, and pricing strategy.
Does Customer Satisfaction Matter to Investors? Findings from the Bond Market
Authors: Anderson Eugene W. , Mansi Sattar A.
Published: September 2009

This article examines whether customer satisfaction is associated with key metrics from corporate bond markets—namely, credit ratings and cost of debt financing. The authors draw on theory in marketing and finance to predict how customer satisfaction should be associated with both measures. To test the hypotheses, they employ the American Customer Satisfaction Index (ACSI) database of more than 150 publicly traded firms during the period from 1994 to 2004. The empirical work controls for factors that are known to influence the bond market, such as firm profitability and risk, as well as potential unobservable factors. The findings indicate that firms with lower customer satisfaction exhibit lower credit ratings and higher debt costs—financial consequences of customer satisfaction not previously observed. The results also suggest that the association between ACSI and cost of debt is attenuated by the inherent level of risk faced by the firm.
Heat-Air-Moisture Transport: Measurements on Building Materials
Authors: Mukhopadhyaya P. , Kumaran M. K.
Published: September 2009

Description

Eleven peer-reviewed papers provide the latest research and standards development activities to assure the reliable, consistent, and meaningful measurement of heat-air-moisture transport through building materials.

Topics cover the importance and necessity of reliably measured hygrothermal material properties and the individual material properties. Some papers identify the need for improvement in existing standards and others point towards new measurement techniques and corresponding standards.
Mechanisms of Atomic Displacements Induced by Radiation
Authors: Sosin A.
Published: September 2009

The earliest theories of radiation effects in metals were based on the simplest assumptions. For example, theoretical treatments of atomic collision have been dominated largely by what may be described as billiard-ball dynamics. These treatments have generally overestimated the “hardness” of the atoms and ignored the inherent anisotropy imposed by the crystallinity of the material. It has become increasingly apparent that a major segment of radiation effects theory that must be improved substantially is in the area of the details of the collision processes. A number of studies, both experimental and theoretical, have contributed notably recently.

It is intended to review this segment of radiation effects theory, bringing under one heading the latest contributions. The review will start with the nature of the original collision and proceed in a straightforward manner through all the stages of the various displacement processes—primary displacements, secondary displacements and cascades, thermal and displacement spikes, and focusing. More precise information concerning interatomic interaction is needed for an accurate description of each of these processes.
Brittle Fracture and Irradiation Effects in Ferritic Pressure Vessel Steels
Authors: Nichols R. W. , Harries D. R.
Published: September 2009

The safe working of any gas-cooled reactor system is dependent on the virtually perfect containment of both fuel and coolant. In order to satisfy these containment requirements, much attention has been given to factors determining the safe working of welded thick-walled steel pressure vessels. In addition to the aspects common to other pressure circuits (stress, temperature, and variations of these) the reactor pressure vessel designer must also consider the effects of neutron bombardment. As a result of neutron irradiation, direct inspection of the reactor pressure vessel during service is not possible and maintenance cannot at present be contemplated. In view of this, and of the serious consequences of failure, somewhat more stringent precautions have to be taken than are common in conventional engineering practice.
Effects of Radiation on Two Low-Alloy Steels at Elevated Temperatures
Authors: Lowe A. L.
Published: September 2009

The effects of temperature during irradiation on the tensile and impact properties of two low-alloy steels were studied. Tension and impact specimens of 1.25Cr-0.5Mo and 2.25Cr-1Mo steels were irradiated in a range of 2.8 x 1018 to 2.0 x 1020 nvt (greater than 1 Mev) and over a temperature range from room temperature to 1700 F.

Results from postirradiation examinations conducted at room temperature indicate that the radiation effects on tensile properties are reduced at irradition temperatures above 725 F and at irradiation temperatures between 900 and 1100 F there is no apparent irradiation damage. For specimens irradiated above approximately 1100 F the tensile and yield strength increased again and strength levels equal to the unirradiated values were not observed until the steel was heated above the A3 point (1630 F). The second increase in tensile and yield strength may be associated with microstructural changes.

Results from subsize impact specimens showed that irradiated data equivalent to the unirradiated impact values were not recovered until temperatures in the stress relief range were reached. At the higher temperatures the shift in impact properties appears to be more sensitive to temperature than to radiation dose.
Swedish Studies on Irradiation Effects in Structural Materials
Authors: Grounes M. , Myers H. P.
Published: September 2009

The irradiation effects studies described here are being carried out by AB Atomenergi (the Atomic Energy Co. of Sweden), a company in which a majority of the shares is held by the state, with private and municipal interests holding the remainder. About 1500 persons are employed of which some 20 per cent are university graduates. The activities of the company are financed by the state, the total grant between 1947 and 1962 amounting to around 145 million dollars. For the financial year 1962-1963 funds totaling 25 million dollars were granted.
Radiation-Induced Property Changes in AISI Type 347 Stainless Steel
Authors: Shober F. R. , Murr W. E.
Published: September 2009

The changes in the mechanical properties of AISI type 347 stainless steel produced by irradiation at ∼120 F to 5.7 × 1021 and 1.2 × 1022 neutrons per sq cm have been determined by tension, impact, and hardness tests. The ultimate strength was increased from 90,000 to 114,000 psi, yield strength was increased from 38,000 to 104,000 psi, and elongation was reduced from 64 to 30 per cent at 75 F. Somewhat smaller changes were obtained at 600 F test temperature. A 1-hr anneal at 1800 F removed all effects of irradiation produced by 1.2 × 1022 neutrons per sq cm and reduced tensile properties at 75 F to essentially the same values as the unirradiated 347 stainless steel. Increased hardness of 347 steel resulting from irradiation was not removed by annealing at 600 F. The energy absorbed at fracture on irradiated Charpy V-notch specimens was 65 ft-lb at 75 F and 20 ft-lb at - 300 F. Sufficient ductility in combination with the increased yield strength would appear to be more than adequate to warrant the service of this material in reactor environments of approximately 120 F to neutron exposures of 1.2 × 1022 neutrons per sq cm.
Effects of Vacuum Melting and Vacuum Annealing on the Properties of Austenitic Stainless Steels
Authors: Roach D. B. , Leffingwell W. B. , Hall A. M.
Published: September 2009

Two applications of vacuum technology to metallurgy are discussed. One concerns the consumable-electrode vacuum-arc remelting of AISI 316 stainless steel. An air-melted and a vacuum-arc remelted heat are compared with respect to composition, processing and welding, room- and high-temperature mechanical properties, magnetic permeability, inclusion count, and behavior in the Huey corrosion test. The vacuum heat was lower in carbon, oxygen, and hydrogen than the air-melted heat. The low oxygen and hydrogen were attributed to the melting process, while the low carbon was not. Both heats were similar in processing and welding behavior as well as in mechanical and physical properties. In Huey corrosion tests of sensitized material, the air-melted steel was attacked much faster than the vacuum-melted material. However, this difference was ascribed to the difference in carbon content between the two steels. Thus, in this study, no differences attributable to the consumable-electrode vacuum-arc remelting process were observed.

The other application was the vacuum annealing of AISI 301 strip. This material was compared with air-annealed and hydrogen-annealed stock. The air-annealed and vacuum-annealed steels had similar mechanical properties. However, the hydrogen-annealed steel had half of the ductility, 80 per cent of the formability and 75 per cent of the strength of the other materials. The increase in hydrogen content of the steel, when annealed in hydrogen, is considered responsible for these differences.
Practical Aspects of Production Bright Annealing of Stainless Steel
Authors: Boyer R. C. , Perrine R. J.
Published: September 2009

Bright annealing is the annealing of stainless steel sheet and strip continuously in a controlled-atmosphere furnace (depicted). The furnace atmosphere system includes an ammonia storage tank, a dissociator, and an adsorption dryer. Furnace capacity depends upon its specific size, source, temperature, and cooling rate, as well as the emissivity of the material processed. Atmosphere problems are purity and nitrogen pickup. Purity of the dissociated ammonia gas depends upon initial raw ammonia contaminants and dissociator performance. Nitrogen pickup can be prevented by annealing in purified hydrogen atmospheres. Production problems include atmosphere system leakage, maintenance of a temperature head, strip cleaning problems, and crystallized surface. Fabrication problems have included soldering and drawing. The advantages of bright annealed strip are improved surface finish, reduced buffing costs, and improved corrosion resistance.
Advancements in Extrusion and Cold Finishing of Stainless Steel Irregular Shapes
Authors: Barrett J. J.
Published: September 2009

Since the beginning of commercial stainless steel extrusion in the United States in 1951, advancements in the technique of extrusion die design, improved extrusion die materials, and improved methods of extrusion die production have broadened the market for extruded steel products, and, more recently, cold finishing of stainless steel irregular shape extrusions has further broadened the market. Multiple orifice die designs, research in the hot work die steel area, electric discharge machine process for finishing of extrusion die orifices, use of EDM for cold draw die production, and correlation of extruded product design to make possible further finishing by cold drawing are refinements in the metal processing industry which have made possible the production of more intricate configurations with closer dimensional control.
Properties of 12 Per Cent Chromium Alloys Modified with Small Columbium Additions
Authors: Tanczyn H.
Published: September 2009

A nominal addition of 0.15 per cent columbium to a heat-hardenable 12 per cent chromium stainless steel (Type 410) is without effect on the general corrosion resistance and quenched hardness of this material. The columbium addition produces a refinement in grain size, a reduced susceptibility to temper embrittlement, a mild improvement in resistance to stress-corrosion cracking, a marked improvement in control of tempered hardness, and an increase in the elevated-temperature mechanical strength of the 12 per cent chromium stainless steel.
A High-Strength Weldable Stainless Steel for Elevated-Temperature Service
Authors: Hull F. C.
Published: September 2009

Based on considerations of hot cracking, tensile, rupture, and creep strength, high-temperature stability, and oxidation resistance, a chromium-nickel-manganese-molybdenum stainless steel strengthened with boron, zirconium, vanadium, and nitrogen was developed. Although rupture and creep strength reached maxima at a level of about 0.17 per cent nitrogen, yield and tensile strength increased linearly with nitrogen to considerably higher levels. Working temperature and reductions and heat treating temperaturs had major effects on the properties. Tungsten-inert-gas welding has been used to join fabricated plate of this alloy into tubing and elbows used for steam-turbine reheat pipe. The nominal composition of this alloy, called Kromarc 58 steel, is 16 per cent chromium, 20 per cent nickel, 10 per cent manganese, 2.25 per cent molybdenum, 0.2 per cent vanadium, 0.25 per cent silicon, 0.01 per cent boron, 0.01 per cent zirconium, 0.04 per cent carbon, 0.17 per cent nitrogen, and balance iron.
The Effects of Neutron Exposure and Reactor Environments on Stainless Steels
Authors: Bush S. H. , Tobin J. C.
Published: September 2009

Stainless steels represent one of the major groups of structural and fuel cladding materials used in nuclear reactors. These steels have been used extensively in civilian power reactors. This paper reviews the performance of ferritic, martensitic, austenitic, and precipitation hardening stainless steels when exposed to neutrons, and the effects of reactor environment, whether water, gas, or liquid metal.

The effects of neutron irradiation on the mechanical properties of stainless steels are examined. Generally, exposure to neutron flux increases the yield strength substantially more than it does the ultimate tensile strength. This is accompanied by marked decreases in ductility. Uniform elongation becomes extremely small after exposures in the range 1020 to 1021 nvt.

The dynamic properties of the stainless steels such as creep, stress rupture, and low cycle fatigue are reviewed, based on the limited data available. The effects of stress application to stainless steels while exposed to neutrons are also discussed.

Specific consideration is given to surface corrosion, oxidation, and stress corrosion where the neutron induced heat flux plays a major role. Potential limitations to the use of these steels by such reactions are considered, as are possible solutions to the problems.

Certain indirect effects of a neutron environment such as thermal cycling due to varying gamma flux during reactor startup and shutdown and the deleterious effects of such cycling are considered in structural components and in fuel cladding. Other indirect effects unique to nuclear reactors such as the interaction of fuel with stainless cladding are discussed briefly.
An Appraisal of Evaluation Tests for Stainless Steel Automotive Trim
Authors: Bates J. F. , Phelps E. H.
Published: September 2009

Within the past few years the automotive industry and the steel producers have been experimenting with a variety of stainless steels for automotive trim exposed to corrosion by road-deicing salts. Several new laboratory tests have been developed to evaluate the corrosion resistance of these steels. In the present study the results of six evaluation tests are tested statistically for significant correlation with the results of service tests conducted on automobiles.

The Dip-and-Dry Test and the Thermographic Test each showed a significant correlation with service-test results. The CASS Test and Spot Test are believed to be effective in detecting surface depletion of chromium, a condition causing poor corrosion resistance. The CASS Test did not, however, predict service performance where there was no surface depletion of chromium. The Ferric Chloride Immersion Test did not have a significant correlation with service. It was, however, extremely sensitive to different surface-finishing operations and may have some merit as a quality control test for a finishing operation. The Corrodkote Test showed no merit for predicting service performance of stainless steel automotive trim.

The absence of any really good correlations with service should lend a note of caution against the extensive use of these evaluation tests. It points to the need for more reliable tests for the evaluation of stainless steel for automotive trim.
Relationship of Heat Treatment and Microstructure to Corrosion Resistance in Wrought Ni-Cr-Mo Alloys
Authors: Streicher M. A.
Published: September 2009

In an investigation of the effect of heat treatment on microstructure and corrosion resistance, seven heats of wrought Ni-Cr-Mo alloy were heated in the range of 800 F to 2375 F. Corrosion was studied in reducing and in oxidizing acids. Oxalic acid etch structures produced by various precipitates were classified and correlated with corrosion rates. Two maxima in corrosion rates were found: one on specimens heated near 1400 F and the other on specimens heated near 1900 F. In hydrochloric acid, only the maximum at 1400 F is revealed, while in chromic acid, only the maximum at 1900 F is detected. Both maxima are revealed by exposure to nitric acid, pure sulfuric acid and ferric sulfate-sulfuric acid solution.

Studies of the microstructures and analysis of residues from dissolution in bromine-methanol solution show that sigma phase, in microscopic or submicroscopic form, is mainly responsible for changes in corrosion resistance produced by heat treatments. carbides of the M6C type containing molybdenum and tungsten as major elements are also present but have a minor effect on corrosion. No chromium carbide, Cr23C6, was found.

Incompletely dissolved precipitates in the form of submicroscopic phases have a deleterious influence on corrosion. Multiple solution-annealing treatments at 2250 F, rather than length of time at temperature, were found most effective in completely dissolving this phase.

Corrosion in reducing acids is under cathodic control. Intergranular attack and the corrosion potentials are a function of the anions of the acid. In oxidizing solutions, corrosion is governed by anodic polarization. The cathodic process consists of reduction of metallic cations. Both grain face and grain boundary zones are passive. Anodic polarization is governed by the presence of such cations as ferric ions and hexavalent chromium ions.

On the basis of data presented, a simple, rapid method for evaluating Ni-Cr-Mo alloys for susceptibility to intergranular attack is, proposed. It consists of electrolytic etching in oxalic acid to detect the presence of incipient fusion resulting from overheating during annealing, and a 24-hour test in boiling solution of ferric sulfate-50 percent sulfuric acid. Material free of all kinds of damaging precipitates has a low rate of corrosion in this test.
A Testing System for Detecting Susceptibility to Rapid Intergranular Attack in Various Grades of Austenitic Stainless Steels
Authors: Streicher M. A.
Published: September 2009

Most of the problems in this field were sharply delineated1 in the “Symposium on Evaluation Tests for Stainless Steels,” held in 1949 by the American Society for Testing and Materials. Investigations on intergranular corrosion undertaken since then have resulted in information and new, rapid testing methods which have largely fulfilled the future needs as defined in the papers and discussions at that time. The purpose of the present paper is to outline a rational testing sequence for evaluating the susceptibility of various grades of stainless steels to rapid intergranular attack by means of a description of the essential characteristics and fields of application of presently available test methods in the light of recent research on intergranular corrosion.