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Accurate diagnosis of bipolar disorder (BPD) is difficult in clinical practice, with an average delay between symptom onset and diagnosis of about 7 years. A depressive episode often precedes the first manic episode, making it difficult to distinguish BPD from unipolar major depressive disorder (MDD).
Aims
We use genome-wide association analyses (GWAS) to identify differential genetic factors and to develop predictors based on polygenic risk scores (PRS) that may aid early differential diagnosis.
Method
Based on individual genotypes from case–control cohorts of BPD and MDD shared through the Psychiatric Genomics Consortium, we compile case–case–control cohorts, applying a careful quality control procedure. In a resulting cohort of 51 149 individuals (15 532 BPD patients, 12 920 MDD patients and 22 697 controls), we perform a variety of GWAS and PRS analyses.
Results
Although our GWAS is not well powered to identify genome-wide significant loci, we find significant chip heritability and demonstrate the ability of the resulting PRS to distinguish BPD from MDD, including BPD cases with depressive onset (BPD-D). We replicate our PRS findings in an independent Danish cohort (iPSYCH 2015, N = 25 966). We observe strong genetic correlation between our case–case GWAS and that of case–control BPD.
Conclusions
We find that MDD and BPD, including BPD-D are genetically distinct. Our findings support that controls, MDD and BPD patients primarily lie on a continuum of genetic risk. Future studies with larger and richer samples will likely yield a better understanding of these findings and enable the development of better genetic predictors distinguishing BPD and, importantly, BPD-D from MDD.
Cross-sectional studies have identified health risks associated with epigenetic aging. However, it is unclear whether these risks make epigenetic clocks ‘tick faster’ (i.e. accelerate biological aging). The current study examines concurrent and lagged within-person changes of a variety of health risks associated with epigenetic aging.
Methods
Individuals from the Great Smoky Mountains Study were followed from age 9 to 35 years. DNA methylation profiles were assessed from blood, at multiple timepoints (i.e. waves) for each individual. Health risks were psychiatric, lifestyle, and adversity factors. Concurrent (N = 539 individuals; 1029 assessments) and lagged (N = 380 individuals; 760 assessments) analyses were used to determine the link between health risks and epigenetic aging.
Results
Concurrent models showed that BMI (r = 0.15, PFDR < 0.01) was significantly correlated to epigenetic aging at the subject-level but not wave-level. Lagged models demonstrated that depressive symptoms (b = 1.67 months per symptom, PFDR = 0.02) in adolescence accelerated epigenetic aging in adulthood, also when models were fully adjusted for BMI, smoking, and cannabis and alcohol use.
Conclusions
Within-persons, changes in health risks were unaccompanied by concurrent changes in epigenetic aging, suggesting that it is unlikely for risks to immediately ‘accelerate’ epigenetic aging. However, time lagged analyses indicated that depressive symptoms in childhood/adolescence predicted epigenetic aging in adulthood. Together, findings suggest that age-related biological embedding of depressive symptoms is not instant but provides prognostic opportunities. Repeated measurements and longer follow-up times are needed to examine stable and dynamic contributions of childhood experiences to epigenetic aging across the lifespan.
One in 57 children are diagnosed with autism in the UK, and the estimated cost for supporting these children in education is substantial. Social Stories™ is a promising and widely used intervention for supporting children with autism in schools and families. It is believed that Social Stories™ can provide meaningful social information to children that can improve social understanding and may reduce anxiety. However, no economic evaluation of Social Stories has been conducted.
Aims
To assess the cost-effectiveness of Social Stories through Autism Spectrum Social Stories in Schools Trial 2, a multi-site, pragmatic, cluster-randomised controlled trial.
Method
Children with autism who were aged 4–11 years were recruited and randomised (N = 249). Costs measured from the societal perspective and quality-adjusted life-years (QALYs) measured by the EQ-5D-Y-3L proxy were collected at baseline and at 6-month follow-up for primary analysis. The incremental cost-effectiveness ratio was calculated, and the uncertainty around incremental cost-effectiveness ratios was captured by non-parametric bootstrapping. Sensitivity analyses were performed to evaluate the robustness of the primary findings.
Results
Social Stories is likely to result in a small cost savings (–£191 per child, 95% CI −767.7 to 337.7) and maintain similar QALY improvements compared with usual care. The probability of Social Stories being a preferred option is 75% if society is willing to pay £20 000 per QALY gained. The sensitivity analysis results aligned with the main study outcomes.
Conclusions
Compared with usual care, Social Stories did not lead to an increase in costs and maintained similar QALY improvements for primary-aged children with autism.
Older age is associated with an increase in altruistic behaviors such as charitable giving. However, few studies have investigated the cognitive correlates of financial altruism in older adults. This study investigated the cognitive correlates of financial altruism measured using an altruistic choice paradigm in a community-based sample of older adults.
Participants and Methods:
In the present study, a sample of older adults (N = 67; M age = 69.21, SD = 11.23; M education years = 15.97, SD = 2.51; 58.2% female; 71.6% Non-Hispanic White) completed a comprehensive neuropsychological assessment and an altruistic choice paradigm in which they made decisions about allocating money between themselves and an anonymous person.
Results:
In multiple linear regression analyses that controlled for age, education, and sex, financial altruism was negatively associated with performance on cognitive measures typically sensitive to early Alzheimer’s Disease. These included CVLT-II Short Delay Free Recall (Beta=-0.26, p=0.03); CVLT-II Long Delay Cued Recall (Beta=-0.32, p=0.04), Craft Story 21 Delayed Recall (Beta=-0.32, p=0.01), and Animal Fluency (Beta=-0.27, p=0.02). Findings held when responses were grouped according to how much was given (Gave Equally, Gave More, Gave Less) for word list memory and story memory measures.
Conclusions:
Findings of this study point to a negative relationship between financial altruism and cognitive functioning in older adults on measures known to be sensitive to Alzheimer’s Disease (AD). Findings also point to a potential link between financial exploitation risk and AD in older age.
In recent years, rates of alcohol consumption and alcohol use disorder have steadily increased among adults age 60 and older. Large studies have demonstrated that moderate-to-heavy alcohol consumption (>7 drinks per week) is a risk factor for developing various types of dementias. The effects of alcohol-related problems on cognition are less clear, and are particularly understudied in older adults. Similarly, while there is an established link between worse cognition and financial exploitation vulnerability in older adults, no studies have examined relationships between alcohol-related problems and financial exploitation in this population. The current study therefore explores whether alcohol-related problems are associated with neuropsychological performance and financial exploitation vulnerability in a sample of older adults.
Participants and Methods:
Participants were a community sample of cognitively unimpaired adults over the age of 50 (N = 55, Age M(SD) = 69.1(6.2), 74.5% female, Years of education M(SD) = 16.8(2.3)). Interested individuals were excluded if they reported current or past substance use disorders. Participants completed a laboratory visit that included a neuropsychological assessment. Measures included the NIH Cognition toolbox, CVLT-II, Digit Span, Trails A/B, Benson Complex Figure Recall, and Verbal Fluency: Phonemic and Semantic, from the Alzheimer’s Disease Centers’ Uniform Data Set (UDS) version 3. Participants completed the CAGE Alcohol Abuse Screening Tool and the Short Michigan Alcohol Screener Test - Geriatric Version (SMAST) to assess alcohol-related problems. Both measures are used as clinical screening tools to measure likelihood of a substance use disorder and produce a summary score (0-4 for CAGE, 010 for SMAST) tabulating symptoms of alcohol-related problems. Participants also completed the Perceived Financial Vulnerability Scale (PFVS) to assess financial exploitation vulnerability. As a significant number of participants reported no drinking and therefore no alcohol-related problems, negative binomial regressions were used to test associations between neuropsychological measures, financial exploitation vulnerability, and alcohol-related problems.
Results:
After covarying for age and sex, SMAST was negatively associated with NIH toolbox total cognition (B(SE) = -.14(.07), p<.05) and marginally negatively associated with fluid cognition (B(SE) = -.07(.04), p=.06). Neither SMAST nor CAGE scores were significantly associated with performance on any other neuropsychological test (ps = .13-.99). SMAST was positively associated with financial exploitation vulnerability (B(SE) = .31(.16), p = .05); this effect remained significant after covarying for NIH total composite score in a secondary analysis.
Conclusions:
In a community sample of cognitively unimpaired, low-drinking adults over the age of 50, more alcohol-related problems were associated with worse NIH toolbox cognition scores. Similarly, more alcohol-related problems were associated with greater financial exploitation vulnerability, and this relationship was not driven by worse cognition. These results suggest that even low amounts of drinking and alcohol-related problems may be associated with cognition and financial exploitation vulnerability in cognitively unimpaired older adults. This study also corroborates the use of the SMAST over the CAGE in older adult populations that may be more sensitive to cognitive changes.
Prior work suggests financial exploitation vulnerability may be an early behavioral manifestation of Alzheimer’s disease (AD). Brain morphometric measures of the parahippocampal gyrus and entorhinal cortex have been shown to be sensitive to early AD progression. We hypothesized that perceived financial exploitation vulnerability may be associated with morphometric measures of the parahippocampal gyrus and entorhinal cortex in cognitively unimpaired older adults. We secondarily investigated the association of morphometric measures with neuropsychological measures.
Participants and Methods:
The sample consisted of 39 cognitively unimpaired older adults (mean age = 68.74 ± 6.43, mean education = 16.87 ± 2.35, 77% female). Cognitive impairment was screened using the telephone version of the Montreal Cognitive Assessment (MoCA) and the cut-off was 21 for study participation. Perceived financial exploitation vulnerability was characterized using a 6-item self-report measure derived from the contextual items of the Lichtenberg Financial Rating Scale. Neuropsychological measures included the CVLT-II Long Delay Free Recall (verbal memory), Benson Complex Figure Recall (visual memory), and Verbal Fluency: Phonemic Test from the Alzheimer’s Disease Centers’ Uniform Data Set (UDS) version 3. Brain images were collected on a 7 Tesla Siemens Magnetom with the following parameters: TE=2.95ms, TR=2200ms, 240 sagittal slices, acquired voxel size (avs)=0.7mm x 0.7mm x 0.7mm. Structural brain images were processed using FreeSurfer version 7.2.0. Cortical thickness and volume measures were generated using the Killiany/Desikian parcellation atlas. Regions were averaged across hemispheres to obtain a single value for each region. Volume measures were adjusted for intracranial volume. Bivariate analyses were conducted to assess relationships between each outcome variable and potential confounders (age, sex, and education). Linear regression models were adjusted for any covariates significantly associated with the outcome variable (none for perceived financial exploitation vulnerability; sex and age for verbal memory; education for visual memory; sex for verbal fluency).
Results:
Smaller entorhinal cortex volume (β = -1275.14, SE = 582.79, p < 0.05) and lower parahippocampal gyrus thickness (β = -3.37, SE = 1.57, p < 0.05) were significantly associated with greater perceived financial exploitation vulnerability. Lower entorhinal cortex thickness was marginally associated with greater perceived financial exploitation vulnerability (β = -2.03, SE = 1.11, p = 0.08). Higher parahippocampal gyrus thickness was associated with better verbal fluency (β = 17.66, SE = 7.01, p < 0.05). Higher entorhinal cortex thickness was associated with better visual memory (β = 4.71, SE = 1.73, p < 0.05). No significant associations were observed between structural brain measures and verbal memory.
Conclusions:
These results suggest smaller entorhinal cortex volume and lower parahippocampal gyrus thickness are associated with higher perceived financial exploitation vulnerability in cognitively normal older adults. Additionally, parahippocampal gyrus thickness appears to be associated with verbal fluency abilities while entorhinal cortex thickness appears to be associated with visual memory. Taken together, these findings lend support to the notion that financial exploitation vulnerability may serve as an early behavioral manifestation of preclinical AD. Longitudinal studies are needed to better understand the temporal nature of these relationships.
Edited by
Dan Chamberlain, University of Turin,Aleksi Lehikoinen, Finnish Museum of Natural History, University of Helsinki,Kathy Martin, University of British Columbia, Vancouver
This chapter summaries what is known about population trends of mountain birds, especially in Europe and North America. A European mountain bird indicator, which summaries the population trends of 44 alpine species, suggests an overall slightly increasing mountain bird population during 2002–2020. Regional North American indicators, based on up to seven alpine species showed either stable or declining trends during 1968–2020. In European mountains, cold-dwelling species had on average less favourable regional population trends than warm-dwelling species, and long-distance migrants tended to have more negative trends than short-distance migrants and residents. There were also spatial differences in trends of the indicators in Europe: mountain birds in general increased in the Alps but decreased in the UK. A comparison between two European breeding bird atlases showed that the distribution area of mountain birds has generally decreased since the 1980s, and mountain specialists have lost more of their range than mountain generalists. Monitoring alpine species presents many challenges which has led to poor coverage in surveys even in areas with well organised bird monitoring programmes at low elevation. The necessary future improvements needed for successful bird population monitoring in mountain areas will, in many instances, require strong financial support.
Structural analysis, petrochronology and metamorphic petrology enable identification and bracketing of the timing of a newly mapped high-temperature ductile shear zone (Jagat Shear Zone (JSZ)) in the Himalayan metamorphic core in Central-Western Nepal. In situ U-Th-Pb monazite petrochronology constrains the timing of top-to-the-S/SW shearing between 28–27 Ma and 17 Ma. Burial and prograde metamorphisms in footwall rocks were linked to thrust-sense movement along the JSZ, while the hanging wall rocks were retrogressed and exhumed. The identification and age of the JSZ (as part of a regional system of shear zones: the High Himalayan Discontinuity (HHD)) coupled with the localization and timing of activity of the Main Central Thrust (MCT) (i) fills a gap in tracing the HHD along orogenic strike, (ii) supports the identification of the position and timing of the long-debated MCT and (iii) helps to place the boundaries of the Himalayan metamorphic core and its internal architecture. Thus, our study is a significant step towards a precise identification of the burial, assembly and exhumation mechanisms of the Himalayan metamorphic core.
Pigmented microalgae inhabiting snow and ice environments lower the albedo of glacier and ice-sheet surfaces, significantly enhancing surface melt. Our ability to accurately predict their role in glacier and ice-sheet surface mass balance is limited by the current lack of empirical data to constrain their representation in predictive models. Here we present new empirical optical properties for snow and ice algae and incorporate them in a radiative transfer model to investigate their impact on snow and ice surface albedo. We found ice algal cells to be more efficient absorbers than snow algal cells, but their blooms had comparable impact on surface albedo due to the different photic conditions of their habitats. We then used the model to reconstruct the effect of ice algae on bare ice albedo spectra collected at our field site in southern Greenland, where blooms dropped the albedo locally by between 3 and 43%, equivalent to 1–10 L m$^{-2}$ d$^{-1}$ of melted ice. Using the newly parametrized model, future studies could investigate biological albedo reduction and algal quantification from remote hyperspectral and multispectral imagery.
The relationship between schizophrenia and violence is complex. The aim of this multicentre case–control study was to examine and compare the characteristics of a group of forensic psychiatric patients with a schizophrenia spectrum disorders and a history of significant interpersonal violence to a group of patients with the same diagnosis but no lifetime history of interpersonal violence.
Method
Overall, 398 patients (221 forensic and 177 non-forensic patients) were recruited across five European Countries (Italy, Germany, Poland, Austria and the United Kingdom) and assessed using a multidimensional standardised process.
Results
The most common primary diagnosis in both groups was schizophrenia (76.4%), but forensic patients more often met criteria for a comorbid personality disorder, almost always antisocial personality disorder (49.1 v. 0%). The forensic patients reported lower levels of disability and better social functioning. Forensic patients were more likely to have been exposed to severe violence in childhood. Education was a protective factor against future violence as well as higher levels of disability, lower social functioning and poorer performances in cognitive processing speed tasks, perhaps as proxy markers of the negative syndrome of schizophrenia. Forensic patients were typically already known to services and in treatment at the time of their index offence, but often poorly compliant.
Conclusions
This study highlights the need for general services to stratify patients under their care for established violence risk factors, to monitor patients for poor compliance and to intervene promptly in order to prevent severe violent incidents in the most clinically vulnerable.
The interpersonal theory of suicide (IPTS) is one of the most intensively researched contemporary theories on the development of suicidal ideation and behaviour. However, there is a lack of carefully conducted prospective studies.
Aims
To evaluate the main predictions of the IPTS regarding the importance of perceived burdensomeness, thwarted belongingness and capability for suicide in predicting future suicide attempts in a prospective design.
Method
Psychiatric in-patients (n = 308; 53.6% (n = 165) female; mean age 36.82 years, s.d. = 14.30, range 18–81) admitted for severe suicidal ideation (n = 145, 47.1%) or a suicide attempt completed self-report measures of thwarted belongingness, perceived burdensomeness, capability for suicide, hopelessness, depression and suicidal ideation as well as interviews on suicide intent and suicide attempts and were followed up for 12 months. Logistic regression and receiver operating characteristics (ROC) analysis were conducted.
Results
The interaction of perceived burdensomeness, thwarted belongingness and capability for suicide was not predictive of future suicide attempts, but perceived burdensomeness showed a significant main effect (z = 3.49, P < 0.01; OR = 2.34, 95% CI 1.59–3.58) and moderate performance in screening for future suicide attempts (area under the curve AUC = 0.729, P < 0.01).
Conclusions
The results challenge the theoretical validity of the IPTS and its clinical utility – at least within the methodological limitations of the current study. Yet, findings underscore the importance of perceived burdensomeness in understanding suicidal ideation and behaviour.
Serious games are a novel and entertaining approach for digital health education in the younger population. Aim of this pilot study was to evaluate the short-term effectiveness of the serious game “Fit, Food, Fun” (FFF) among a subset of children and adolescents in Germany with regard to nutritional knowledge.
Materials and Methods:
Two Bavarian secondary schools were each allocated to one intervention arm. The gameplay intervention (gameplay group; GG) consisted of a 15-minute gameplay session for each of three days (Tuesday to Thursday), while the teaching intervention (teaching group; TG) was performed as a 15-minute classic lecture for the same number of days. Given nutritional information was based on the recommendations of the “German Nutrition Society e.V.” and was identical for both intervention groups. Nutritional knowledge was evaluated through a standardised questionnaire at baseline (Monday) and post-intervention (Friday). Lifestyle behaviour (diet; physical activity) and anthropometrics (height; weight) were assessed once at baseline. Inclusion criteria were sufficient German language skills and parental consent form. Statistical analyses were performed using the statistical software R (R Core Team, 2018).
Results:
In total, 47 students (62% male) were assigned to the GG and 47 students (72% male) to the TG. The mean age was 13.5 years in the GG and 12.8 years in the TG. The mean body mass index was in the normal range (GG: 24.4 kg/m2; TG: 22.0 kg/m2). Data at baseline and post-intervention are analysed for 36 participants in the GG and for 40 participants in the TG. Compared to baseline, results revealed significant improvements (p-value < 0.001) in nutritional knowledge in both intervention groups. There was a between-group difference with significantly (p-value = 0.0139) higher increase of nutritional knowledge in the TG.
Discussion:
This pilot study provides evidence for the short-term efficacy of both game-based and traditional education approaches on the improvement of nutritional knowledge; however, further research in warranted to assess the potential effect of a digital gameplay intervention on nutritional behaviour. Finally, the FFF game might be considered as an appropriate educational tool for imparting nutritional knowledge in an entertaining and effective format among children and adolescents.
To assess the consumption of sugar-sweetened beverages (SSB) and other energy-dense nutrient-poor (EDNP) foods in two Southern low-income communities targeted by the Balance Calories Initiative, a campaign by the top-three American beverage companies intended to reduce the consumption of sugary beverages by 20 % over 10 years.
Design:
We conducted self-administered intercept surveys in front of food retail outlets between August and November 2016. We recruited adults with children <18 years living at home and adolescents aged 10–17 years with parental consent.
Setting:
Retail food outlets in Mississippi and Alabama, USA.
Participants:
Adults (n 11 311) and adolescents (n 3460).
Results:
The percentage of high SSB consumers (≥4 servings/d) was 40·9 % among adult males, 32·3 % among adult females, 43·0 % among adolescent males and 34·4 % among adolescent females (male – female difference, P < 0·0001). In aggregate, respondents also reported consuming a mean of 3 servings of salty snacks, cookies and/or candy in the past 24 h, with adolescent males reporting 4 servings.
Conclusions:
SSB should be a primary target of future interventions to improve dietary intake, but EDNP foods likely contribute as many daily kilojoules as SSB among this population. Future campaigns should aim to limit the consumption of all EDNP foods.
We argue in this chapter that environmental perspectives have the potential to enrich models of successful aging. Importantly, theories of successful aging have so far largely ignored the role of contextual influences; this is where this chapter steps in. Our reasoning is grounded in the field of environmental gerontology which strives to understand the relationship of aging individuals to their environments as well as its utilization and optimization to effectively support individuals/families with varying conditions, capabilities, and needs. First, we provide an overview of established models able to contribute to the understanding of how older adults have interchange with their environments. Doing so, we address traditional theories such as the competence-press model as well as more recent approaches such as Golant’s model of residential normalcy and the motivational theory of life-span development. Second, we elaborate on the connection between environmental gerontology reasoning and successful aging, for example by highlighting the critical role of environments for aging with disabilities. Third, we consider issues of interventions located at the environmental level and also address the challenges of implementation, hence to make sustainable changes in home and clinical environments in order to support successful aging.
Lead white is a man-made white pigment commonly used in works of art. In this study, the possibility of radiocarbon dating lead white pigments alone and in oil paints was explored using well-dated lead white pigments and paints. Resulting 14C ages on lead white pigments produced following the traditional stack process, where carbonate groups results from the incorporation of CO2 originating from fermentation, matched the production years, while radiocarbon dating of lead white made using other industrial processes indicate that 14C depleted CO2 was used in their production. The method was applied to two case studies, where lead carbonate samples were dated in two oil paintings, one Baroque and one from the 20th century. We hereby show that the lead white pigment can be dated by 14C and used as proxy for the time of creation of an artwork. Additionally, a two-step method was developed to allow 14C analysis of both the lead white pigment and oil binder from the same sample. A single lead white paint sample can yield two distinct radiocarbon ages, one from the carbonate and one from the natural organic binder. This study thus proposes new strategies for 14C dating of artworks.
Despite the fact that urbanisation, population ageing and international migration constitute major societal developments of our time, little attention has been paid to studying them together in a comprehensive manner. In this paper, we argue that, when treating age and ethnicity as practical processes for addressing and identifying with social groups, it is necessary to do so from a ‘doing’ perspective. The question we ask focuses on which social memberships are made relevant or irrelevant in residential environments and how that relevance or irrelevance is established. Drawing upon a quantitative study among individuals of Turkish migrant origin living in Vienna, Austria, we find that it is rather common for the respondents to have been assigned to multiple intersecting social groups and that they were treated unfairly in their own neighbourhoods. However, such ascriptions do not necessarily correspond to objective categorisations of research or subjective identifications. Hence, the discrimination that is present in a neighbourhood does not necessarily lead to decreased place attachment or a diminishing sense of home. In fact, we find that the ‘satisfaction paradox’ is quite common in environmental gerontology and that it may actually intersect with the ‘immigration paradox’. Applying processual intersectionality is not only fruitful for research, it can also improve the conceptualisation of age-friendly cities.
The use of accelerator mass spectrometry (AMS) for age determinations of paintings is growing due to decreasing sample size requirements. However, as only the support material is usually dated, the validity of the results may be questioned. This work describes a novel sampling and preparation technique for dating the natural organic binder using radiocarbon (14C) AMS. In the particular case of oil paintings, the natural oil used has a high probability of being representative of the time of creation, hereby circumventing the problem of the originality of the support material. A multi-technique approach was developed for a detailed characterization of all paint components to identify the binder type as well as pigments and additives present in the sample. The technique was showcased on a painting of the 20th century. The results by 14C AMS dating show that both the canvas and binding medium predate the signed date by 4–5 yr. This could be the time span for keeping painting material in the atelier. The method developed provides, especially given the low amounts of material needed for analysis, a superior precision and accuracy in dating and has potential to become a standard method for oil painting dating.
The results of extensive experimental testing of an aero-engine air-oil separator are presented and discussed. The study focuses on the pressure loss of the system. Oil enters the device in the form of dispersed droplets. Subsequently, separation occurs by centrifuging larger droplets towards the outer walls and by film formation at the inner surface of a rotating porous material, namely an open-cell metal foam. The work described here is part of a study led jointly by the Karlsruhe Institute of Technology (KIT) and the University of Nottingham (UNott) within a recent EU project.
The goal of the research is to increase the separation efficiency to mitigate oil consumption and emissions, while keeping the pressure loss as low as possible. The aim is to determine the influencing factors on pressure loss and separation efficiency. With this knowledge, a correlation can eventually be derived. Experiments were conducted for three different separator configurations, one without a metal foam and two with metal foams of different pore sizes. For each configuration, a variety of engine-like conditions of air mass flow rate, rotational speed and droplet size was investigated. The experimental results were used to validate and improve the numerical modelling.
Results for the pressure drop and its dependencies on air mass flow rate and the rotational speed were analysed. It is shown that the swirling flow and the dissipation of angular momentum are the most important contributors to the pressure drop, besides the losses due to friction and dissipation caused by the flow passing the metal foam. It was found that the ratio of the rotor speed and the tangential velocity of the fluid is an important parameter to describe the influence of rotation on the pressure loss. Contrary to expectations, the pressure loss is not necessarily increased with a metal foam installed.