bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Developments in the R5 Volume 2/3 Procedures for Assessing Creep-Fatigue Initiation in Defect-Free Components Operating at High Temperatures
Authors: Dean David W. , Spindler Michael W. , Chevalier Marc , Smith N. Godfrey 
Published: January 2014

The R5 procedures have been developed within the UK power generation industry to assess the integrity of nuclear and conventional plant operating at high temperatures. Within R5, there are specific procedures for assessing creep-fatigue crack initiation in initially defect-free components (Volume 2/3) and procedures for assessing components containing defects (Volume 4/5).
Recent developments in the R5 Volume 2/3 procedure for assessing creep-fatigue initiation in defect-free components include improved methods for predicting creep damage and a new approach for assessing weldments. The improved methods for predicting creep damage include the option of using the stress-modified ductility exhaustion (SMDE) approach as an alternative to the existing ductility exhaustion approach, together with improved methods for assessing compressive dwells. The new approach for assessing weldments involves splitting the existing Fatigue Strength Reduction Factor (FSRF) into a Weldment Endurance Reduction (WER), which accounts for reduced fatigue endurance due to weld imperfections, and a Weldment Strain Enhancement Factor (WSEF), which accounts for material mismatch and local geometry effects.
This paper briefly outlines the current R5 Volume 2/3 procedures and then focuses on these two significant recent developments in the procedures.
Numerical Simulation of Hot Cracking Tests
Authors: Le Minh , Asserin Olivier , Forest Laurent , Fandeur Olivier , Pilvin Philippe 
Published: January 2014

One of the main nuclear materials is the austenitic stainless steels, which have good ductility and toughness, high thermal expansion coefficients and a thermal conductivity lower than that of martensitic or ferritic steels. The 316L(N) austenitic stainless steel (X2CrNiMo17-12-2 with controlled nitrogen) is evaluated for structures such as the vessels, which are steel enclosures surrounding the reactor core and its assemblies, in fourth generation nuclear systems.
The RCC-MR code, which is used as a frame of reference in the manufacture of SFR (Sodium Fast Reactor concept), recommends the use of austenoferritic filler material for the welding of 316L(N) steel. These recommendations derive from past experience of working with fast neutron reactors (Phenix and Superphenix). In order to guarantee long-term properties at high temperatures, an austenoferritic and an austenitic filler metals are evaluated as filler metals.
However, these materials are susceptible to hot cracking. Therefore, a study is conducted to ensure their weldability. The purpose of this work is to evaluate the susceptibility to hot cracking of the studied materials and to present a methodology applied to define a criterion called “laboratory” for each material and its transfer to a structure test.
The relative susceptibility to hot cracking of these materials was evaluated using four tests: the Varestraint, the Gleeble, the trapezoid and the skew tests. Numerical simulation using Cast3M code and Sidolo software of these four tests were investigated in order to survey behavior laws of each studied material and solidification cracking thermomechanical criteria intrinsic to the materials. Some test and simulation results as well as hot cracking susceptibility ranking are presented and the transferability to real component welds of hot cracking criteria is discussed.
Towards local progression estimation of pulmonary emphysema using CT
Authors: Staring M. , Bakker M. E. , Stolk J. , Shamonin D. P. , Reiber J. H. C. , Stoel B. C. 
Published: January 2014

Purpose:Whole lung densitometry on chest CT images is an accepted method for measuring tissue destruction in patients with pulmonary emphysema in clinical trials. Progression measurement is required for evaluation of change in health condition and the effect of drug treatment. Information about the location of emphysema progression within the lung may be important for the correct interpretation of drug efficacy, or for determining a treatment plan. The purpose of this study is therefore to develop and validate methods that enable the local measurement of lung density changes, which requires proper modeling of the effect of respiration on density.Methods:Four methods, all based on registration of baseline and follow‐up chest CT scans, are compared. The first naïve method subtracts registered images. The second employs the so‐called dry sponge model, where volume correction is performed using the determinant of the Jacobian of the transformation. The third and the fourth introduce a novel adaptation of the dry sponge model that circumvents its constant‐mass assumption, which is shown to be invalid. The latter two methods require a third CT scan at a different inspiration level to estimate the patient‐specific density‐volume slope, where one method employs a global and the other a local slope. The methods were validated on CT scans of a phantom mimicking the lung, where mass and volume could be controlled. In addition, validation was performed on data of 21 patients with pulmonary emphysema.Results:The image registration method was optimized leaving a registration error below half the slice increment (median 1.0 mm). The phantom study showed that the locally adapted slope model most accurately measured local progression. The systematic error in estimating progression, as measured on the phantom data, was below 2 gr/l for a 70 ml (6%) volume difference, and 5 gr/l for a 210 ml (19%) difference, if volume correction was applied. On the patient data an underlying linearity assumption relating lung volume change with density change was shown to hold (fitR2 = 0.94), and globalized versions of the local models are consistent with global results (R2 of 0.865 and 0.882 for the two adapted slope models, respectively).Conclusions:In conclusion, image matching and subsequent analysis of differences according to the proposed lung models (i) has good local registration accuracy on patient data, (ii) effectively eliminates a dependency on inspiration level at acquisition time, (iii) accurately predicts progression in phantom data, and (iv) is reasonably consistent with global results in patient data. It is therefore a potential future tool for assessing local emphysema progression in drug evaluation trials and in clinical practice.
Improving the energy response of external beam therapy (EBT) GafChromicTM dosimetry films at low energies (≤100 keV)
Authors: Bekerat H. , Devic S. , DeBlois F. , Singh K. , Sarfehnia A. , Seuntjens J. , Shih Shelley , Yu Xiang , Lewis D. 
Published: January 2014

Purpose:Purpose of this work is to investigate the effects of varying the active layer composition of external beam therapy (EBT) GafChromicTM films on the energy dependence of the film, as well as try to develop a new prototype with more uniform energy response at low photon energies (⩽100 keV).Methods:First, the overall energy response (SAD, W(Q)) of different commercial EBT type film models that represent the three different generations produced to date, i.e., EBT, EBT2, and EBT3, was investigated. Pieces of each film model were irradiated to a fixed dose of 2 Gy to water for a wide range of beam qualities and the corresponding SAD, W(Q) was measured using a flatbed document scanner. Furthermore, the DOSRZnrc Monte Carlo code was used to determine the absorbed dose to water energy dependence of the film, f(Q). Moreover, the intrinsic energy dependence, kbq(Q), for each film model was evaluated using the corresponding SAD, W(Q) and f(Q). In the second part of this study, the authors investigated the effects of changing the chemical composition of the active layer on SAD, W(Q). Finally, based on these results, the film manufacturer fabricated several film prototypes and the authors evaluated their SAD, W(Q).Results:The commercial EBT film model shows an under response at all energies below 100 keV reaching 39% ± 4% at about 20 keV. The commercial EBT2 and EBT3 film models show an under response of about 27% ± 4% at 20 keV and an over response of about 16% ± 4% at 40 keV.SAD, W(Q) of the three commercial film models at low energies show strong correlation with the corresponding f−1(Q) curves. The commercial EBT3 model with 4% Cl in the active layer shows under response of 22% ± 4% at 20 keV and 6% ± 4% at about 40 keV. However, increasing the mass percent of chlorine makes the film more hygroscopic which may affect the stability of the filmˈs readout. The EBT3 film prototype with 7.5% Si shows a significant improvement in the energy response at very low energies compared to the commercial EBT3 films with 4% Cl. It shows under response of 15% ± 5% at about 20 keV to 2% ± 5% at about 40 keV. However, according to the manufacturer, the addition of 7.5% Si as SiO2 adversely affected the viscosity of the active fluid and therefore affected the potential use in commercial machine coating. The latest commercial EBT3 film model with 7% Al as Al2O3 shows an overall improvement in SAD, W(Q) compared to previous commercial EBT3 films. It shows under response at all energies <100 keV, varying from 20% ± 4% at 20 keV to 6% ± 4% at 40 keV.Conclusions:The energy response of films in the energy range <100 keV can be improved by adjusting the active layer chemical composition. Removing bromine eliminated the over response at about 40 keV. The under response at energies ≤30 keV is improved by adding 7% Al to the active layer in the latest commercial EBT3 film models.
Determination of prescription dose for Cs‐131 permanent implants using the BED formalism including resensitization correction
Authors: Luo Wei , Molloy Janelle , Aryal Prakash , Feddock Jonathan , Randall Marcus 
Published: January 2014

Purpose:The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear‐quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs‐131.Methods:A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au‐198, I‐125, and Pd‐103 were converted to the isoeffective Cs‐131 prescription doses. The conversion factor F, ratio of the Cs‐131 dose to the equivalent dose with the other reference isotope (Fr: with resensitization, Fn: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation.Results:Prescription doses with I‐125, Pd‐103, and Au‐198 ranging from 10 to 160 Gy were converted into prescription doses with Cs‐131. The difference in dose conversion factors with (Fr) and without (Fn) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I‐125, the average values of Fr/Fn were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd‐103, the average values of Fr/Fn were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au‐198, the average values of Fr/Fn were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4‐I cells, the averaged value of Fr was 1.07/1.11 (rounded to 1.1), and the averaged value of Fn was 1.75/1.18. Fr of 1.1 has been applied to gynecological cancer implants with expected acute reactions and outcomes as expected based on extensive experience with permanent implants. The calculation also gave the average Cs‐131 dose of 126 Gy converted from the I‐125 dose of 144 Gy for prostate implants.Conclusions:Inclusion of an allowance for resensitization led to significant dose corrections for Cs‐131 permanent implants, and should be applied to prescription dose calculation. The adjustment of the Cs‐131 prescription doses with resensitization correction for gynecological permanent implants was consistent with clinical experience and observations. However, the Cs‐131 prescription doses converted from other implant doses can be further adjusted based on new experimental results, clinical observations, and clinical outcomes.
High energy x‐ray phase contrast CT using glancing‐angle grating interferometers
Authors: Sarapata A. , Stayman J. W. , Finkenthal M. , Siewerdsen J. H. , Pfeiffer F. , Stutman D. 
Published: January 2014

Purpose:The authors present initial progress toward a clinically compatible x‐ray phase contrast CT system, using glancing‐angle x‐ray grating interferometry to provide high contrast soft tissue images at estimated by computer simulation dose levels comparable to conventional absorption based CT.Methods:DPC‐CT scans of a joint phantom and of soft tissues were performed in order to answer several important questions from a clinical setup point of view. A comparison between high and low fringe visibility systems is presented. The standard phase stepping method was compared with sliding window interlaced scanning. Using estimated dose values obtained with a Monte‐Carlo code the authors studied the dependence of the phase image contrast on exposure time and dose.Results:Using a glancing angle interferometer at high x‐ray energy (∼45 keV mean value) in combination with a conventional x‐ray tube the authors achieved fringe visibility values of nearly 50%, never reported before. High fringe visibility is shown to be an indispensable parameter for a potential clinical scanner. Sliding window interlaced scanning proved to have higher SNRs and CNRs in a region of interest and to also be a crucial part of a low dose CT system. DPC‐CT images of a soft tissue phantom at exposures in the range typical for absorption based CT of musculoskeletal extremities were obtained. Assuming a human knee as the CT target, good soft tissue phase contrast could be obtained at an estimated absorbed dose level around 8 mGy, similar to conventional CT.Conclusions:DPC‐CT with glancing‐angle interferometers provides improved soft tissue contrast over absorption CT even at clinically compatible dose levels (estimated by a Monte‐Carlo computer simulation). Further steps in image processing, data reconstruction, and spectral matching could make the technique fully clinically compatible. Nevertheless, due to its increased scan time and complexity the technique should be thought of not as replacing, but as complimentary to conventional CT, to be used in specific applications.
Monte Carlo based beam model using a photon MLC for modulated electron radiotherapy
Authors: Henzen D. , Manser P. , Frei D. , Volken W. , Neuenschwander H. , Born E. J. , Vetterli D. , Chatelain C. , Stampanoni M. F. M. , Fix M. K. 
Published: January 2014

Purpose:Modulated electron radiotherapy (MERT) promises sparing of organs at risk for certain tumor sites. Any implementation of MERT treatment planning requires an accurate beam model. The aim of this work is the development of a beam model which reconstructs electron fields shaped using the Millennium photon multileaf collimator (MLC) (Varian Medical Systems, Inc., Palo Alto, CA) for a Varian linear accelerator (linac).Methods:This beam model is divided into an analytical part (two photon and two electron sources) and a Monte Carlo (MC) transport through the MLC. For dose calculation purposes the beam model has been coupled with a macro MC dose calculation algorithm. The commissioning process requires a set of measurements and precalculated MC input. The beam model has been commissioned at a source to surface distance of 70 cm for a Clinac 23EX (Varian Medical Systems, Inc., Palo Alto, CA) and a TrueBeam linac (Varian Medical Systems, Inc., Palo Alto, CA). For validation purposes, measured and calculated depth dose curves and dose profiles are compared for four different MLC shaped electron fields and all available energies. Furthermore, a measured two‐dimensional dose distribution for patched segments consisting of three 18 MeV segments, three 12 MeV segments, and a 9 MeV segment is compared with corresponding dose calculations. Finally, measured and calculated two‐dimensional dose distributions are compared for a circular segment encompassed with a C‐shaped segment.Results:For 15 × 34, 5 × 5, and 2 × 2 cm2fields differences between water phantom measurements and calculations using the beam model coupled with the macro MC dose calculation algorithm are generally within 2% of the maximal dose value or 2 mm distance to agreement (DTA) for all electron beam energies. For a more complex MLC pattern, differences between measurements and calculations are generally within 3% of the maximal dose value or 3 mm DTA for all electron beam energies. For the two‐dimensional dose comparisons, the differences between calculations and measurements are generally within 2% of the maximal dose value or 2 mm DTA.Conclusions: The results of the dose comparisons suggest that the developed beam model is suitable to accurately reconstruct photon MLC shaped electron beams for a Clinac 23EX and a TrueBeam linac. Hence, in future work the beam model will be utilized to investigate the possibilities of MERT using the photon MLC to shape electron beams.
The design and fabrication of two portal vein flow phantoms by different methods
Authors: Yunker Bryan E. , Dodd Gerald D. , Chen S. James , Chang Samuel , Lanning Craig J. , Scherzinger Ann L. , Shandas Robin , Feng Yusheng , Hunter Kendall S. 
Published: January 2014

Purpose:This study outlines the design and fabrication techniques for two portal vein flow phantoms.Methods:A materials study was performed as a precursor to this phantom fabrication effort and the desired material properties are restated for continuity. A three‐dimensional portal vein pattern was created from the Visual Human database. The portal vein pattern was used to fabricate two flow phantoms by different methods with identical interior surface geometry using computer aided design software tools and rapid prototyping techniques. One portal flow phantom was fabricated within a solid block of clear silicone for use on a table with Ultrasound or within medical imaging systems such as MRI, CT, PET, or SPECT. The other portal flow phantom was fabricated as a thin walled tubular latex structure for use in water tanks with Ultrasound imaging. Both phantoms were evaluated for usability and durability.Results:Both phantoms were fabricated successfully and passed durability criteria for flow testing in the next project phase.Conclusions:The fabrication methods and materials employed for the study yielded durable portal vein phantoms.
Importance of Standardized DXA Protocol for Assessing Physique Changes in Athletes
Authors: Nana Alisa , Slater Gary J. , Hopkins Will G. , Halson Shona L. , Martin David T. , West Nicholas P. , Burke Louise M. 
Published: January 2014

Purpose:The implications of undertaking DXA scans using best practice protocols (subjects fasted and rested) or a less precise but more practical protocol in assessing chronic changes in body composition following training and a specialized recovery technique were investigated.Methods:Twenty-one male cyclists completed an overload training program, in which they were randomized to four sessions per week of either cold water immersion therapy or control groups. Whole-body DXA scans were undertaken with best practice protocol (Best) or random activity protocol (Random) at baseline, after 3 weeks of overload training, and after a 2-week taper. Magnitudes of changes in total, lean and fat mass from baseline-overload, overload-taper and baseline-taper were assessed by standardization (Δmean/SD).Results:The standard deviations of change scores for total and fat-free soft tissue mass (FFST) from Random scans (2–3%) were approximately double those observed in the Best (1–2%), owing to extra random errors associated with Random scans at baseline. There was little difference in change scores for fat mass. The effect of cold water immersion therapy on baseline-taper changes in FFST was possibly harmful (-0.7%; 90% confidence limits ±1.2%) with Best scans but unclear with Random scans (0.9%; ±2.0%). Both protocols gave similar possibly harmful effects of cold water immersion therapy on changes in fat mass (6.9%; ±13.5% and 5.5%; ±14.3%, respectively).Conclusions:An interesting effect of cold water immersion therapy on training-induced changes in body composition might have been missed with a less precise scanning protocol. DXA scans should be undertaken with Best.
Genome Sequence of the
Sulfitobacter
sp. Strain 2047-Infecting Lytic Phage ΦCB2047-B
Authors: Ankrah Nana Y. D. , Budinoff Charles R. , Wilson William H. , Wilhelm Steven W. , Buchan Alison 
Published: January 2014

ABSTRACT

We announce the complete genome sequence of a lytic podovirus, ΦCB2047-B, which infects the bacterium
Sulfitobacter
sp. strain 2047, a member of the
Roseobacter
clade. Genome analysis revealed ΦCB2047-B to be an N4-like phage, with its genome having high nucleotide similarity to other N4-like roseophage genomes.
Draft Genome Sequence of the Bioelectricity-Generating and Dye-Decolorizing Bacterium Proteus hauseri Strain ZMd44
Authors: Wang Nan , Ng I-Son , Chen Po Ting , Li Yuzhe , Chen Yi-Chung , Chen Bor-Yann , Lu Yinghua 
Published: January 2014

ABSTRACT

Proteus hauseri
ZMd44 (CGMCC 6746), as a crucial biodecolorizing, bioelectricity-generating, and copper-resistant bacterium, is distinguished from the urinary pathogens
Proteus penneri
and
Proteus mirabilis
. To further investigate the genetic functions of this strain, the genome sequence and annotation of its open reading frames, which consist of 3,875,927 bp (G+C content, 38.12%), are presented here.
Full-Genome Sequences of Influenza A(H1N1)pdm09 Viruses Isolated from Finnish Patients from 2009 to 2013
Authors: Lakspere Triin , Tynell Janne , Kaloinen Minttu , Vanlede Maarten , Parsons Alun , Ikonen Niina , Kallio-Kokko Hannimari , Kantele Anu , Mattila Pirkko , Almusa Henrikki , Julkunen Ilkka , Kainov Denis , Kakkola Laura 
Published: January 2014

ABSTRACT
Here we report full-length sequencing of the first large set of influenza A(H1N1)pdm09 virus genomes isolated in Finland between the years 2009 and 2013 and discuss the advantages and needs of influenza virus sequencing efforts.
Draft Genome Sequences of Type Strain Sediminibacterium salmoneum NJ-44 and
Sediminibacterium
sp. Strain C3, a Novel Strain Isolated from Activated Sludge
Authors: Ayarza Joaquín M. , Figuerola Eva L. M. , Erijman Leonardo 
Published: January 2014

ABSTRACT

The genus
Sediminibacterium
comprises species present in diverse natural and engineered environments. Here, we report for the first time the genome sequences of the type strain
Sediminibacterium salmoneum
NJ-44 (NBRC 103935) and
Sediminibacterium
sp. strain C3 (BNM541), isolated from activated sludge, a valuable model for the study of substrate-dependent autoaggregation.
A Circo-Like Virus Isolated from Penaeus monodon Shrimps
Authors: Pham Hanh T. , Yu Qian , Boisvert Maude , Van Hanh T. , Bergoin Max , Tijssen Peter 
Published: January 2014

ABSTRACT

A virus with a circular Rep-encoding single-stranded DNA (ssDNA) (CRESS-DNA) genome (PmCV-1) was isolated from
Penaeus monodon
shrimps in Vietnam. The gene structure of the 1,777-nucleotide (nt) genome was similar to that of circoviruses and cycloviruses, but the nucleic acid and protein sequence identities to these viruses were very low.