Korrosions- und Verschleißeigenschaften auftraggeschweißter Duplexstahlschichten: Eine Frage des Gefüges

Die erfolgreiche Erhöhung der Lebensdauer von korrosiv und tribologisch beanspruchten Bauteilen durch Auftragschweißen von Duplexstahlschichten mit beanspruchungsgerechten Eigenschaften auf Gusseisen mit Lamellengraphit erfordert detaillierte Kenntnisse um die Beeinflussung der Eigenschaften durch den Beschichtungsprozess. Es wurden verschiedene Lichtbogenschweißverfahren und Vorwärmtemperaturen zur Herstellung der Auftragschweißschichten angewendet, um trotz der sehr spezifischen und sehr unterschiedlichen Anforderungen der beiden Werkstoffe an die Wärmeführung während des Schweißens flächige Auftragschweißschichten zu erzielen. Die chemischen Aufmischungen und Phasenverteilungen, die Mikrohärten und Eindringhärten, die Korrosions- und Verschleißeigenschaften sowie die Beständigkeiten unter Strömungserosions- und Kavitationsbeanspruchungen wurden für verschiedene Bereiche dieser Auftragschweißschichten vergleichend untersucht. Als Vergleich wurden kommerziell hergestellter Duplexstahl und Gusseisen mit Lamellengraphit herangezogen. Unter nahezu sämtlichen Beanspruchungen wurde durch die Auftragschweißschichten eine verbesserte Beständigkeit gegenüber Gusseisen mit Lamellengraphit erzielt, teilweise vergleichbar und manchmal sogar deutlich besser als reiner Duplexstahl. Die unterschiedlichen Eigenschaften, beispielsweise die Stabilität einer Passivschicht in künstlichem Meerwasser wurden auf die unterschiedlichen Bedingungen während des Auftragschweißens zurückgeführt, aus denen Variationen in Aufmischung und Gefüge resultierten. Geringe Energieeinbringung durch den Lichtbogen bewirkt niedrige Aufmischungen und hohe Abkühlgeschwindigkeiten, die Schichten erstarren schnell und mit teilweise hohen Eigenspannungen, was in Kombination mit Martensitbildung in der Wärmeeinflusszone zu Rissbildung im Grundwerkstoff führen kann. Diffusion und Phasenumwandlungen werden gehemmt, wodurch in Abhängigkeit der chemischen Zusammensetzung Duplexgefüge aus Ferrit und Austenit entstehen. Durch Vorwärmung des Grundwerkstoffs schmilzt dieser in höherem Maße, die Aufmischung steigt und die Abkühlgeschwindigkeiten sinken, wodurch Diffusion und Phasenumwandlungen vermehrt stattfinden können. In der Arbeit werden die Ergebnisse der Charakterisierungen, die Beanspruchbarkeiten und die Korrosions- und Verschleißmechanismen der einzelnen Schichten geklärt und umfassend in Bezug auf die Schweißprozesse diskutiert. Daraus wird abgeleitet, welche Gefüge in Abhängigkeit der Aufmischung und der Wärmeführung beim Auftragschweißen entstehen, welche Eigenschaften diese haben und schließlich, wie durch die Prozessführung beim Auftragschweißen gezielte Eigenschaften eingestellt werden können. Über diese Arbeit hinausgehend können dann die Auftragschweißschichten gezielt auf die Beanspruchungsprofile in der Anwendung hergestellt werden

Caring for the elderly:A person-centered segmentation approach for exploring the association between health care needs, mental health care use, and costs in Germany

BACKGROUND: Person-centered care demands the evaluation of needs and preferences of the patients. In this study, we conducted a segmentation analysis of a large sample of older people based on their bio-psycho-social-needs and functioning. The aim of this study was to clarify differences in health care use and costs of the elderly in Germany. METHODS: Data was derived from the 8-year follow-up of the ESTHER study-a German epidemiological study of the elderly population. Trained medical doctors visited n = 3124 participants aged 57 to 84 years in their home. Bio-psycho-social health care needs were assessed using the INTERMED for the Elderly (IM-E) interview. Further information was measured using questionnaires or assessment scales (Barthel index, Patients Health Questionnaire (PHQ) etc.). The segmentation analysis applied a factor mixture model (FMM) that combined both a confirmatory factor analysis and a latent class analysis. RESULTS: In total, n = 3017 persons were included in the study. Results of the latent class analysis indicated that a five-cluster-model best fit the data. The largest cluster (48%) can be described as healthy, one cluster (13.9%) shows minor physical complaints and higher social support, while the third cluster (24.3%) includes persons with only a few physical and psychological difficulties ("minor physical and psychological complaints"). One of the profiles (10.5%) showed high and complex bio-psycho-social health care needs ("complex needs") while another profile (2.5%) can be labelled as "frail". Mean values of all psychosomatic variables-including the variable health care costs-gradually increased over the five clusters. Use of mental health care was comparatively low in the more burdened clusters. In the profiles "minor physical and psychological complaints" and "complex needs", only half of the persons suffering from a mental disorder were treated by a mental health professional; in the frail cluster, only a third of those with a depression or anxiety disorder received mental health care. CONCLUSIONS: The segmentation of the older people of this study sample led to five different clusters that vary profoundly regarding their bio-psycho-social needs. Results indicate that elderly persons with complex bio-psycho-social needs do not receive appropriate mental health care

Associations of frailty with health care costs – results of the ESTHER cohort study

Background: The concept of frailty is rapidly gaining attention as an independent syndrome with high prevalence in older adults. Thereby, frailty is often related to certain adverse outcomes like mortality or disability. Another adverse outcome discussed is increased health care utilization. However, only few studies examined the impact of frailty on health care utilization and corresponding costs. The aim of this study was therefore to investigate comprehensively the relationship between frailty, health care utilization and costs. Methods: Cross sectional data from 2598 older participants (57–84 years) recruited in the Saarland, Germany, between 2008 and 2010 was used. Participants passed geriatric assessments that included Fried’s five frailty criteria: weakness, slowness, exhaustion, unintentional weight loss, and physical inactivity. Health care utilization was recorded in the sectors of inpatient treatment, outpatient treatment, pharmaceuticals, and nursing care. Results: Prevalence of frailty (≥3 symptoms) was 8.0 %. Mean total 3-month costs of frail participants were €3659 (4 or 5 symptoms) and €1616 (3 symptoms) as compared to €642 of nonfrail participants (no symptom). Controlling for comorbidity and general socio-demographic characteristics in multiple regression models, the difference in total costs between frail and non-frail participants still amounted to €1917; p < .05 (4 or 5 symptoms) and €680; p < .05 (3 symptoms). Among the 5 symptoms of frailty, weight loss and exhaustion were significantly associated with total costs after controlling for comorbidity. Conclusions: The study provides evidence that frailty is associated with increased health care costs. The analyses furthermore indicate that frailty is an important factor for health care costs independent from pure age and comorbidity. Costs were rather attributable to frailty (and comorbidity) than to age. This stresses that the overlapping concepts of multimorbidity and frailty are both necessary to explain health care use and corresponding costs among older adults

When people fall from grace: Reconsidering the role of envy in Schadenfreude

Previous research yielded conflicting results concerning the role of envy in predicting Schadenfreude (pleasure at another's misfortune). Some studies showed that envy predicts Schadenfreude, whereas others did not. Results of the present research reconcile these opposing findings, by showing that envy is a predictor of Schadenfreude when the target is similar to the observer in terms of gender. These results suggest that envy predicts Schadenfreude when people are confronted with the misfortune of a relevant social comparison other. Copyright 2006 by the American Psychological Association

Effects of gain—loss frames on satisfaction with self–other outcome-differences

This research concerned satisfaction with outcome-differences (advantageous inequity, equity, or disadvantageous inequity) as a function of the individual's gain or loss frame, other's gain or loss frame, the cooperative or noncooperative nature of the relationship, and their interactions. After reading a scenario, subjects rated on a satisfaction-dissatisfaction soak a series of outcome-pairs providing themselves and another party with outcomes. Consistent with Equity Theory, results showed that gain framed individuals found equity more pleasing than advantageous inequity, which in turn was preferred over disadvantageous inequity, but only when the decision making context was cooperative rather than noncooperative. In a noncooperative context, gain framed individuals were as pleased with equity as with advantageous inequity. Contrary to Equity Theory, but consistent with Prospect Theory, loss framed individuals were relatively insensitive to outcome-differences and the nature of the relationship. Results finally suggested that advantageous inequity was preferred less when the other party had a loss rather than gain frame, albeit only under cooperative circumstances

Measurement of the Lifetime Difference Between B_s Mass Eigenstates

We present measurements of the lifetimes and polarization amplitudes for B_s --> J/psi phi and B_d --> J/psi K*0 decays. Lifetimes of the heavy (H) and light (L) mass eigenstates in the B_s system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203 +/- 15 B_s decays, we obtain tau_L = (1.05 +{0.16}/-{0.13} +/- 0.02) ps and tau_H = (2.07 +{0.58}/-{0.46} +/- 0.03) ps. Expressed in terms of the difference DeltaGamma_s and average Gamma_s, of the decay rates of the two eigenstates, the results are DeltaGamma_s/Gamma_s = (65 +{25}/-{33} +/- 1)%, and DeltaGamma_s = (0.47 +{0.19}/-{0.24} +/- 0.01) inverse ps.Comment: 8 pages, 3 figures, 2 tables; as published in Physical Review Letters on 16 March 2005; revisions are for length and typesetting only, no changes in results or conclusion

Measurement of WγW\gamma and ZγZ\gamma Production in ppˉp\bar{p} Collisions at s\sqrt{s} = 1.96 TeV

The Standard Model predictions for $W\gamma$ and $Z\gamma$ production are tested using an integrated luminosity of 200 pb$^{-1}$ of \ppbar collision data collected at the Collider Detector at Fermilab. The cross sections are measured selecting leptonic decays of the $W$ and $Z$ bosons, and photons with transverse energy $E_T>7$ GeV that are well separated from leptons. The production cross sections and kinematic distributions for the $W\gamma$ and $Z\gamma$ are compared to SM predictions.Comment: 7 pages, 4 figures, submitted to PR

Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV

We present a search for ZZ and ZW vector boson pair production in ppbar collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an integrated luminosity of 194 pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0 +/- 0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys. Rev. D Rapid Communication

Measurement of the Cross Section for Prompt Diphoton Production in p-pbar Collisions at sqrt(s) = 1.96 TeV

We report a measurement of the rate of prompt diphoton production in $p\bar{p}$ collisions at $\sqrt{s}=1.96 ~\hbox{TeV}$ using a data sample of 207 pb$^{-1}$ collected with the upgraded Collider Detector at Fermilab (CDF II). The background from non-prompt sources is determined using a statistical method based on differences in the electromagnetic showers. The cross section is measured as a function of the diphoton mass, the transverse momentum of the diphoton system, and the azimuthal angle between the two photons and is found to be consistent with perturbative QCD predictions.Comment: 7 pages, 3 figures,revtex4. Version accepted by PRL, but with cross section tables i

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s}=1.96 TeV using Lepton + Jets Events with Secondary Vertex b-tagging

We present a measurement of the ttbar production cross section using events with one charged lepton and jets from ppbar collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb-1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 +- 1.8 events are expected from background contributions. We measure a ttbar production cross section of 5.6^{+1.2}_{-1.1} (stat.) ^{+0.9}_{0.6} (syst.) pb.Comment: 28 pages, 20 figures. Published in Physical Review