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1.
Eur Radiol ; 33(6): 4228-4236, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36905469

ABSTRACT

OBJECTIVES: To provide insights for on-site development of transformer-based structuring of free-text report databases by investigating different labeling and pre-training strategies. METHODS: A total of 93,368 German chest X-ray reports from 20,912 intensive care unit (ICU) patients were included. Two labeling strategies were investigated to tag six findings of the attending radiologist. First, a system based on human-defined rules was applied for annotation of all reports (termed "silver labels"). Second, 18,000 reports were manually annotated in 197 h (termed "gold labels") of which 10% were used for testing. An on-site pre-trained model (Tmlm) using masked-language modeling (MLM) was compared to a public, medically pre-trained model (Tmed). Both models were fine-tuned on silver labels only, gold labels only, and first with silver and then gold labels (hybrid training) for text classification, using varying numbers (N: 500, 1000, 2000, 3500, 7000, 14,580) of gold labels. Macro-averaged F1-scores (MAF1) in percent were calculated with 95% confidence intervals (CI). RESULTS: Tmlm,gold (95.5 [94.5-96.3]) showed significantly higher MAF1 than Tmed,silver (75.0 [73.4-76.5]) and Tmlm,silver (75.2 [73.6-76.7]), but not significantly higher MAF1 than Tmed,gold (94.7 [93.6-95.6]), Tmed,hybrid (94.9 [93.9-95.8]), and Tmlm,hybrid (95.2 [94.3-96.0]). When using 7000 or less gold-labeled reports, Tmlm,gold (N: 7000, 94.7 [93.5-95.7]) showed significantly higher MAF1 than Tmed,gold (N: 7000, 91.5 [90.0-92.8]). With at least 2000 gold-labeled reports, utilizing silver labels did not lead to significant improvement of Tmlm,hybrid (N: 2000, 91.8 [90.4-93.2]) over Tmlm,gold (N: 2000, 91.4 [89.9-92.8]). CONCLUSIONS: Custom pre-training of transformers and fine-tuning on manual annotations promises to be an efficient strategy to unlock report databases for data-driven medicine. KEY POINTS: • On-site development of natural language processing methods that retrospectively unlock free-text databases of radiology clinics for data-driven medicine is of great interest. • For clinics seeking to develop methods on-site for retrospective structuring of a report database of a certain department, it remains unclear which of previously proposed strategies for labeling reports and pre-training models is the most appropriate in context of, e.g., available annotator time. • Using a custom pre-trained transformer model, along with a little annotation effort, promises to be an efficient way to retrospectively structure radiological databases, even if not millions of reports are available for pre-training.


Subject(s)
Radiology , Humans , Databases, Factual , Natural Language Processing , Radiology/methods , Retrospective Studies , Color
2.
J Phys Condens Matter ; 34(50)2022 Oct 28.
Article in English | MEDLINE | ID: mdl-36261038

ABSTRACT

X-ray resonant Raman spectroscopy (XRRS), a variant of resonant inelastic x-ray scattering, has been used to investigate the two prototype systems, UF4and UO2. Both are U5f2and each is an example of 5f localized, ionic behavior and 5f localized, covalent behavior, respectively. From the M5XRRS measurements, the 5f band gap in each can be directly determined and, moreover, a clear and powerful sensitivity to 5f covalency emerges.

3.
J Phys Condens Matter ; 33(49)2021 Sep 27.
Article in English | MEDLINE | ID: mdl-34507312

ABSTRACT

Time resolved pump and probe acoustics and first-principles calculations were employed to assess elastic properties of the TbMnO3perovskite manganite having orthorhombic symmetry. Measuring sound velocities of bulk longitudinal and shear acoustic waves propagating along at least two different directions in the high symmetry planes (100), (010) and (001), provided a powerful mean to selectively determine the six diagonal elastic constantsC11= 227 GPa,C22= 349 GPa,C33= 274 GPa,C44= 71 GPa,C55= 57 GPa,C66= 62 GPa. Among the three remaining off-diagonal ones,C23= 103 GPa was determined with a bissectrice direction. Density functional theory calculations with colinear spin-polarized provided complementary insights on their optical, elastic and magnetoelastic properties.

4.
J Dent Res ; 100(11): 1220-1227, 2021 10.
Article in English | MEDLINE | ID: mdl-34077690

ABSTRACT

Dental care professionals (DCPs) are thought to be at enhanced risk of occupational exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, robust data to support this from large-scale seroepidemiological studies are lacking. We report a longitudinal seroprevalence analysis of antibodies to SARS-CoV-2 spike glycoprotein, with baseline sampling prior to large-scale practice reopening in July 2020 and follow-up postimplementation of new public health guidance on infection prevention control (IPC) and enhanced personal protective equipment (PPE). In total, 1,507 West Midlands DCPs were recruited into this study in June 2020. Baseline seroprevalence was determined using a combined IgGAM enzyme-linked immunosorbent assay and the cohort followed longitudinally for 6 mo until January/February 2021 through the second wave of the coronavirus disease 2019 pandemic in the United Kingdom and vaccination commencement. Baseline seroprevalence was 16.3%, compared to estimates in the regional population of 6% to 7%. Seropositivity was retained in over 70% of participants at 3- and 6-mo follow-up and conferred a 75% reduced risk of infection. Nonwhite ethnicity and living in areas of greater deprivation were associated with increased baseline seroprevalence. During follow-up, no polymerase chain reaction-proven infections occurred in individuals with a baseline anti-SARS-CoV-2 IgG level greater than 147.6 IU/ml with respect to the World Health Organization international standard 20-136. After vaccination, antibody responses were more rapid and of higher magnitude in those individuals who were seropositive at baseline. Natural infection with SARS-CoV-2 prior to enhanced PPE was significantly higher in DCPs than the regional population. Natural infection leads to a serological response that remains detectable in over 70% of individuals 6 mo after initial sampling and 9 mo from the peak of the first wave of the pandemic. This response is associated with protection from future infection. Even if serological responses wane, a single dose of the Pfizer-BioNTech 162b vaccine is associated with an antibody response indicative of immunological memory.


Subject(s)
COVID-19 , Vaccines , Dental Care , Humans , SARS-CoV-2 , Seroepidemiologic Studies , United Kingdom/epidemiology
5.
Rev Sci Instrum ; 91(3): 033101, 2020 Mar 01.
Article in English | MEDLINE | ID: mdl-32259983

ABSTRACT

We present a high energy resolution x-ray spectrometer for the tender x-ray regime (1.6-5.0 keV) that was designed and operated at Stanford Synchrotron Radiation Lightsource. The instrument is developed on a Rowland geometry (500 mm of radius) using cylindrically bent Johansson analyzers and a position sensitive detector. By placing the sample inside the Rowland circle, the spectrometer operates in an energy-dispersive mode with a subnatural line-width energy resolution (∼0.32 eV at 2400 eV), even when an extended incident x-ray beam is used across a wide range of diffraction angles (∼30° to 65°). The spectrometer is enclosed in a vacuum chamber, and a sample chamber with independent ambient conditions is introduced to enable a versatile and fast-access sample environment (e.g., solid/gas/liquid samples, in situ cells, and radioactive materials). The design, capabilities, and performance are presented and discussed.

7.
Phys Rev Lett ; 122(15): 155003, 2019 Apr 19.
Article in English | MEDLINE | ID: mdl-31050499

ABSTRACT

The excitation mechanism for low-n edge harmonic oscillations in quiescent H-mode regimes is identified analytically. We show that the combined effect of diamagnetic and poloidal magnetohydrodynamic flows, with the constraint of a Doppler-like effect of the ion flow, leads to the stabilization of short wavelength modes, allowing low-n perturbation to grow. The analysis, performed in tokamak toroidal geometry, includes the effects of large edge pressure gradients, associated with the local flattening of the safety factor and diamagnetic flows, sheared parallel and E×B rotation, and a vacuum region between plasma and the ideal metallic wall. The separatrix also is modeled analytically.

8.
Clin Neurol Neurosurg ; 173: 154-158, 2018 10.
Article in English | MEDLINE | ID: mdl-30142621

ABSTRACT

OBJECTIVES: Hydrocephalus can be defined as clinically symptomatic dilatation of the internal ventricular system at the expense of brain and blood volume. Shunt insertion is the mainstay of therapy for communicating hydrocephalus. One of the most frequently used valves is the programmable Codman Medos Hakim valve which enables the pressure level to be adjusted from 30 to 200 mmH2O. The problem of functional over- or underdrainage and the associated complications should be significantly reduced if not excluded. Especially in the clinical application of the Codman Medos Hakim Shunt System in hydrocephalus of other etiology only a few studies can be found. This study aims to increase knowledge of both the safety of Codman Medos valves with SiphonGuard in the clinical application as well as the correct choice of the pressure level for different indications. PATIENTS AND METHODS: In this retrospective study, 101 patients were included who underwent surgery with the adjustable "Codman Medos Hakim" valve with "SiphonGuard" between January 2010 and July 2013. We analyzed the patient files and imaging (CCT, cMRT) data. The statistical examinations were performed using the WINStat program for Excel. RESULTS: Our results show that an initial pressure level of 120mmH2O proved to be suitable in all subgroups. After optimization of the initial pressure level 70.3% of the valves (71 valves) had a pressure level of 120mmH2O. Importantly, only in the SAH subgroup the clinical improvement was correlated with a reduction in the measured indices. But in all subgroups a clinical deterioration was associated with an increased ventricular size. CONCLUSION: Overall, the clinical data show that an initial pressure level of 120mmH2O seems to be appropriate for most patients treated in this series. Measured indices from the cranial imaging can provide valuable indications for the presence of a suboptimal valve setting for the individual patient.


Subject(s)
Cerebrospinal Fluid Shunts , Hydrocephalus/surgery , Postoperative Complications/etiology , Prostheses and Implants , Adolescent , Adult , Cerebrospinal Fluid Pressure/physiology , Cerebrospinal Fluid Shunts/instrumentation , Child , Child, Preschool , Equipment Design , Female , Humans , Infant , Male , Middle Aged , Young Adult
9.
BMC Cardiovasc Disord ; 18(1): 146, 2018 07 13.
Article in English | MEDLINE | ID: mdl-30005637

ABSTRACT

BACKGROUND: It has been suggested that changes in pulmonary veins (PV) and left atrium (LA) anatomy may have an influence on initiating atrial fibrillation (AF) and the effectiveness of pulmonary vein isolation (PVI) in patients (pts) with atrial fibrillation. The aim of the study was to assess anatomy abnormalities of the PV and LA in the patients with the history of AF and compare it with the control group(CG). METHODS: The multi-slice tomography (MSCT) scans were performed in 224 AF pts. before PVI (129 males, mean age 59 ± 9 yrs). The CG consisted of 40 pts. without AF (26 males, age 45 ± 9 yrs). LA and PV anatomy were evaluated. Diameters of PV ostia were measured in two directions: anterior-posterior (AP) and superior-inferior (SI) automatically using Vitrea 4.0. RESULTS: Pulmonary veins anatomy variants were observed more frequently in the atrial fibrillation group - 83 pts. (37%) vs 6 pts. (15%) in CG; 9% (21 pts) left common ostia (CO), 2% (5 pts) right CO, 19% (42 pts) additional right PV (APV), (1.8%) 4 pts. APV left, 8% right early branching (EB) and 3.5% left EB. The LA diameter differed significantly in AF vs CG group (41.2 ± 6 mm vs 35 ± 4.2 mm, p < 0.0001) respectively. CONCLUSIONS: The anomalies of pulmonary vein anatomy occurred more often in pts. with AF. They can be defined as an image biomarkers of atrial fibrillation. Right additional (middle) pulmonary vein was the most important anomaly detected in AF patients as well as enlargered diameters of the LA and PV ostia.


Subject(s)
Atrial Fibrillation/diagnostic imaging , Computed Tomography Angiography/methods , Multidetector Computed Tomography/methods , Phlebography/methods , Pulmonary Veins/abnormalities , Pulmonary Veins/diagnostic imaging , Adult , Aged , Atrial Fibrillation/etiology , Atrial Fibrillation/surgery , Case-Control Studies , Female , Heart Atria/diagnostic imaging , Humans , Male , Middle Aged , Predictive Value of Tests , Pulmonary Veins/surgery , Risk Factors , Young Adult
10.
RSC Adv ; 8(21): 11785-11798, 2018 Mar 21.
Article in English | MEDLINE | ID: mdl-35558550

ABSTRACT

ZnO-ZnS 1D hetero-nanostructures were prepared by an easy and scalable processing route. It consists of ZnO nanorod electrodeposition on ITO substrate and surface sulfidation by ion exchange in an aqueous Na2S solution. Increasing the treatment contact time (t c) from 8 to 48 h involves different ZnS growth mechanisms leading to different structural and microstructural rod characteristics, even if the overall size does not change significantly. Grazing X-ray diffraction, high-resolution microscopy, energy-dispersive spectrometry and X-ray photoelectron spectroscopy describe the outer surface layer as a poly- and nanocrystalline ZnS blende shell whose thickness and roughness increase with t c. The ZnO wurtzite-ZnS blende interface goes from continuous and dense, at short t c, to discontinuous and porous at long t c, indicating that ZnS formation proceeds in a more complex way than a simple S2-/O2- ion exchange over the treatment time. This feature has significant consequences for the photoelectrochemical performance of these materials when they are used as photoanodes in a typical light-assisted water splitting experiment. A photocurrent (J p) fluctuation of 45% for less than 5 min of operation is observed for the sample prepared with a long sulfidation time while it does not exceed 15% for that obtained with a short one, underlining the importance of the material processing conditions on the preparation of valuable photoanodes.

12.
J Dent Res ; 96(11): 1314-1321, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28767323

ABSTRACT

Nonsyndromic cleft palate only (nsCPO) is a facial malformation that has a livebirth prevalence of 1 in 2,500. Research suggests that the etiology of nsCPO is multifactorial, with a clear genetic component. To date, genome-wide association studies have identified only 1 conclusive common variant for nsCPO, that is, a missense variant in the gene grainyhead-like-3 ( GRHL3). Thus, the underlying genetic causes of nsCPO remain largely unknown. The present study aimed at identifying rare variants that might contribute to nsCPO risk, via whole-exome sequencing (WES), in multiply affected Central European nsCPO pedigrees. WES was performed in 2 affected first-degree relatives from each family. Variants shared between both individuals were analyzed for their potential deleterious nature and a low frequency in the general population. Genes carrying promising variants were annotated for 1) reported associations with facial development, 2) multiple occurrence of variants, and 3) expression in mouse embryonic palatal shelves. This strategy resulted in the identification of a set of 26 candidate genes that were resequenced in 132 independent nsCPO cases and 623 independent controls of 2 different ethnicities, using molecular inversion probes. No rare loss-of-function mutation was identified in either WES or resequencing step. However, we identified 2 or more missense variants predicted to be deleterious in each of 3 genes ( ACACB, PTPRS, MIB1) in individuals from independent families. In addition, the analyses identified a novel variant in GRHL3 in 1 patient and a variant in CREBBP in 2 siblings. Both genes underlie different syndromic forms of CPO. A plausible hypothesis is that the apparently nonsyndromic clefts in these 3 patients might represent hypomorphic forms of the respective syndromes. In summary, the present study identified rare variants that might contribute to nsCPO risk and suggests candidate genes for further investigation.


Subject(s)
Cleft Palate/genetics , Exome/genetics , Europe , Female , Genetic Predisposition to Disease , Genetic Variation , Humans , Male , Sequence Analysis, DNA , Yemen
13.
Phys Chem Chem Phys ; 18(38): 26595-26601, 2016 Sep 29.
Article in English | MEDLINE | ID: mdl-27711648

ABSTRACT

The changes in electrolyte composition on the molecular level and the reaction mechanisms of electrolyte degradation upon thermal aging are monitored by quantitative NMR spectroscopy, revealing similar rates of degradation for pristine and already aged electrolytes. The data analysis is not in favor of an autocatalytic reaction mechanism based on OPF3 but rather indicates that the degradation of LiPF6 in carbonate based solvents proceeds via a complex sequence of "linear" reactions rather than a cyclic reaction pattern which is determined by the amount of water present in the samples. All investigated electrolytes are reasonably stable at temperatures of up to 60 °C in the presence of minor amounts or absence of water hence indicating that chemical instability of electrolyte components against water is decisive for degradation and an increase in temperature ("thermal aging") just accelerates the degradation impact of water.

14.
Child Care Health Dev ; 42(5): 683-91, 2016 09.
Article in English | MEDLINE | ID: mdl-27273161

ABSTRACT

BACKGROUND: The introduction of the International Classification of Functioning, Disabilities and Health of the World Health Organization in 2001 made social participation a major rehabilitation outcome and the ultimate goal of rehabilitation services. There is no available instrument to measure the youth participation in leisure activities apart from asking the youth themselves. The goal of this study was to present a German version of the Children's Assessment of Participation and Enjoyment and Preferences for Activities of Children (CAPE/PAC). METHODS: The CAPE/PAC questionnaire was translated into German, a cultural adaptation process was designed and a reliability study was conducted. One hundred and fifty-two youths with and without disabilities, with a mean age of 15.2 years (standard deviation 1.7), participated in the study. The participants completed CAPE and PAC twice within 4 weeks. Reliability was examined by intraclass correlation coefficients, standard error of measurement, smallest detectable change and Cronbach's alpha. RESULTS: The absolute values of participation differ between the typically developed youth group and those with impairments; the reliability of the CAPE/PAC is comparable in both groups. Intraclass correlation coefficients ranged from 0.43 to 0.74 for the CAPE and from 0.71 to 0.83 for the PAC in all participants. The alpha values for internal consistency ranged from 0.42 to 0.82 for the CAPE and from 0.65 to 0.92 for the PAC. CONCLUSIONS: The German version of the PAC showed satisfactory reliability; however, reliability was not satisfactory for all scores of the CAPE, but comparable with versions in other languages. The need for newly developed participation measurements requires further discussion.


Subject(s)
Interpersonal Relations , Leisure Activities/psychology , Social Participation , Adolescent , Child , Chronic Disease , Disabled Children/psychology , Female , Focus Groups , Germany , Humans , Male , Reproducibility of Results , Surveys and Questionnaires , Translating
15.
Phys Chem Chem Phys ; 18(5): 3956-65, 2016 Feb 07.
Article in English | MEDLINE | ID: mdl-26771035

ABSTRACT

The 1st cycle Coulombic efficiency (CE) of LiNi1/3Co1/3Mn1/3O2 (NCM) at 4.6 V vs. Li/Li(+) has been extensively investigated in NCM/Li half cells. It could be proven that the major part of the observed overall specific capacity loss (in total 36.3 mA h g(-1)) is reversible and induced by kinetic limitations, namely an impeded lithiation reaction during discharge. A measure facilitating the lithiation reaction, i.e. a constant potential (CP) step at the discharge cut-off potential, results in an increase in specific discharge capacity of 22.1 mA h g(-1). This capacity increase during the CP step could be proven as a relithiation process by Li(+) content determination in NCM via an ICP-OES measurement. In addition, a specific capacity loss of approx. 4.2 mA h g(-1) could be determined as an intrinsic reaction to the NCM cathode material at room temperature (RT). In total, less than 10.0 mA h g(-1) (=28% of the overall capacity loss) can be attributed to irreversible reactions, mainly to irreversible structural changes of NCM. Thus, the impact of parasitic reactions, such as oxidative electrolyte decomposition, on the irreversible capacity is negligible and could also be proven by on-line MS. As a consequence, the determination of the amount of extracted Li(+) ("Li(+) extraction ratio") so far has been incorrect and must be calculated by the charge capacity (=delithiation amount) divided by the theoretical capacity. In a NCM/graphite full cell the relithiation amount during the constant voltage (CV) step is smaller than in the half cell, due to irreversible Li(+) loss at graphite.

16.
Environ Sci Pollut Res Int ; 22(23): 19170-83, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26250811

ABSTRACT

An approach consisting in combining in situ and laboratory experiments is often favoured for investigating the mechanisms involved in the weathering of the materials of the cultural heritage. However, the realistic simulation in the laboratory of the environmental conditions ruling the interactions of atmospheric compounds with materials is a very complex task. The aim of this work is to characterise CIME, a new chamber specially built to simulate the interactions between materials of the cultural heritage and the environment. The originality of this instrument is that beside the usual climatic parameters (temperature, relative humidity, solar radiation) and gaseous pollutants, it also allows the controlled injection of different types of particulate matter such as terrigenous, marine and anthropogenic. Therefore, varied realistic atmospheric environments (marine or urban) can be easily simulated within CIME. In addition to the technical description of CIME, this paper shows the first results obtained by the impact of gaseous pollutants on non-durable glass, bronze and limestone. The first experiments for the deposition of different particles (calcite, clays, soot and halite) are also presented.


Subject(s)
Air Pollutants/chemistry , Materials Testing/instrumentation , Particulate Matter/chemistry , Alloys/chemistry , Calcium Carbonate/chemistry , Carbon Dioxide/chemistry , Carbonates/chemistry , Cities , Crystallization , Glass/chemistry , Nitrogen Dioxide/chemistry , Particle Size , Soot/chemistry , Strontium/chemistry , Temperature , Weather
17.
Dalton Trans ; 44(36): 16013-23, 2015 Sep 28.
Article in English | MEDLINE | ID: mdl-26285686

ABSTRACT

New hybrid compounds LnCoCl(deg)2 (deg = diethyleneglycolate; Ln = Nd, Sm, Eu, Gd and Ho) have been synthesized by mixing cobalt and rare earth cations in a boiling diethyleneglycol (degH2) medium. Their crystallographic structures have been ab initio solved from synchrotron powder diffraction data. They consist of edge sharing tetrameric sub-units [(Ln2Co2)(deg)4(Cl)2] forming 1D infinite chains along the c parameter of a monoclinic unit cell (SG = C2/c). The five- and seven-coordination of Co(2+) and Ln(3+) cations inferred from the crystallographic results is confirmed by UV-visible absorption and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. In the LnCoCl(deg)2 (Ln = Nd, Sm, Eu, Gd, Ho) series, weak antiferromagnetic superexchange interactions have been evidenced, between high spin Co(2+) and Ln(3+) orbitally degenerate cations. These materials are considered as potential precursors for the simultaneous reduction of Co-Ln-glycolate species into bimetallic nanoparticles by the polyol process.

18.
J Dent Res ; 93(4): 376-81, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24563486

ABSTRACT

Nonsyndromic orofacial clefting (nsOFC) is a common, complex congenital disorder. The most frequent forms are nonsyndromic cleft lip with or without cleft palate (nsCL/P) and nonsyndromic cleft palate only (nsCPO). Although they are generally considered distinct entities, a recent study has implicated a region around the FOXE1 gene in both nsCL/P and nsCPO. To investigate this hypothesis, we analyzed the 2 most strongly associated markers (rs3758249 and rs4460498) in 2 independent samples of differing ethnicities: Central European (949 nsCL/P cases, 155 nsCPO cases, 1163 controls) and Mayan Mesoamerican (156 nsCL/P cases, 10 nsCPO cases, 338 controls). While highly significant associations for both single-nucleotide polymorphisms were obtained in nsCL/P (rs4460498: p Europe = 6.50 × 10(-06), p Mayan = .0151; rs3758249: p Europe = 2.41 × 10(-05), p Mayan = .0299), no association was found in nsCPO (p > .05). Genotyping of rs4460498 in 472 independent European trios revealed significant associations for nsCL/P (p = .016) and nsCPO (p = .043). A meta-analysis of all data revealed a genomewide significant result for nsCL/P (p = 1.31 × 10(-08)), which became more significant when nsCPO cases were added (p nsOFC = 1.56 × 10(-09)). These results strongly support the FOXE1 locus as a risk factor for nsOFC. With the data of the initial study, there is now considerable evidence that this locus is the first conclusive risk factor shared between nsCL/P and nsCPO.


Subject(s)
Cleft Lip/genetics , Cleft Palate/genetics , Forkhead Transcription Factors/genetics , Genetic Variation/genetics , Case-Control Studies , Chromosome Mapping , Ethnicity/genetics , Female , Genes, Recessive/genetics , Genotype , Homozygote , Humans , Indians, Central American/genetics , Linkage Disequilibrium/genetics , Male , Models, Genetic , Phenotype , Polymorphism, Single Nucleotide/genetics , Risk Factors , White People/genetics
19.
Rev Sci Instrum ; 82(11): 113506, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22133575

ABSTRACT

A Martin Puplett interferometer for electron cyclotron emission (ECE) measurements from JET tokamak plasmas was extended to multichannel operation for simultaneous radial and oblique ECE measurements. This paper describes the new optics and the instrument's performance.

20.
J Mech Behav Biomed Mater ; 4(8): 1864-72, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22098885

ABSTRACT

A flash-thermal treatment technique has been developed very recently to improve both the critical stress to induce the martensitic transformation (MT) and the recoverable deformation of the metastable ß type titanium alloys. In this paper, this strategy is applied to both Ti-26Nb and Ti-20Nb-6Zr (at.%) alloys. Since both alloys have identical martensite start (Ms) temperature, it makes possible to investigate the effect of Zr on mechanical properties after the flash-thermal treatment. It is clearly shown that a flash treatment of 360 s at 873 K on heavily cold-rolled samples results in good balance between the tensile strength, the ductility and the recoverable strains. Such contribution is more significant in the ternary alloy in which balanced properties combining high martensitic critical stress over 400 MPa and the large fully recoverable strains up to 3.0% can be achieved. These improvements are due to the flash treatment effects, resulting in ultra-fine ß grains with sizes 1-2 µm with nano-sized α and ω phases precipitation in the ß matrix.


Subject(s)
Alloys/chemistry , Elasticity , Niobium/chemistry , Temperature , Titanium/chemistry , Zirconium/chemistry , Materials Testing , Tensile Strength
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