376 research outputs found

    An Elastomeric Energy Storage System to Improve Vehicle Efficiency.

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    Most regenerative braking systems studied hitherto have made use of batteries, tlywheels and hydraulic accumulators. The present study has investigated the use of elastomers for such systems. The ability of elastomers to store large amounts of energy, together with the fact that this energy can be recovered quickly, makes them attractive materials for propulsion devices and inherently simple to engineer. Theoretical and experimental research has shown that the development of an elastomeric regenerative braking system does appear to be technically feasible. The predicted rubber characteristics have been compared with the known characteristics of a conventional engine. The results show that the tractive effort produced by the elastomer is capable of matching the characteristics of the engine considered in this work. Rates of input and output energy have also been calculated to determine the process of energy storage and retrieval throughout a typical driving cycle. The energy store appears to be capable of reproducing many stages of the three driving cycles considered. When there is insufticient energy in the system, power boosts from the conventional engine are required. In order to increase the overall savings achieved by the system, the engine was 'replaced' by one which had force (and therefore power) characteristics of one half of the conventional engine initially considered. It was found that the reduced power engine was sufficient to supply the extra power boosts as required. In addition to reduced engine and brake wear, fuel consumption and emissions have been shown to be drastically reduced. If these values could be achieved in practice, the benefits of such a system are immediately apparent. The potential financial savings available to the car user corresponding to the decrease in fuel consumption would provide a strong incentive. Environmentally the benefits are two fold, firstly the reduction in pollution emissions means cleaner air and has an impact on global warming, and secondly reduced fuel consumption means that fossil fuel reserves may last considerably longer than currently predicted thus reducing the immediate need for alternatives sources

    Water wave propagation and scattering over topographical bottoms

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    Here I present a general formulation of water wave propagation and scattering over topographical bottoms. A simple equation is found and is compared with existing theories. As an application, the theory is extended to the case of water waves in a column with many cylindrical steps

    Disorder-specific patterns of emotion coregulation in couples: Comparing obsessive compulsive disorder and anorexia nervosa

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    Impaired emotion regulation and maladaptive strategies to manage distress are central to psychopathology, including obsessive-compulsive disorder (OCD) and anorexia nervosa (AN). Emotion regulation can be fostered or thwarted by romantic partners, and the tendency to rely on interpersonally oriented emotion regulation may vary by disorder. This study examined coregulation as a form of interpersonal emotion regulation in OCD and AN. We hypothesized that OCD is associated with exaggerated and AN with diminished coregulation, and that OCD patients have greater overall levels of emotional arousal than AN patients. Greater symptom severity was expected to exacerbate these opposing tendencies. Vocally encoded emotional arousal was measured during couple conversations in 34 AN patients, 18 OCD patients, and their partners. Two indicators of coregulation (covariation and coupling) were analyzed using cross-lagged actor-partner interdependence and coupled linear oscillator models. As hypothesized, OCD was associated with greater overall emotional arousal than AN. Symptom severity was not associated with emotional arousal or coregulation. Covariation differed in the opposite direction of the hypothesis; there was no difference in coupling. AN patients exhibited consistent coregulation, indicating high reactivity to partners' emotional arousal which may contribute to interpersonal avoidance. OCD couples showed limited predictability of patients' arousal over time, while partners were affected by the patients' emotional arousal; thus, symptom accommodation may in part be partners' attempts at managing their own distress along with the patients'. A better understanding of interpersonal emotion regulation in OCD and AN can inform treatment by targeting interaction patterns that may maintain symptoms

    Relationship between advanced maternal age and timing of first developmental evaluation in children with autism

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    Objective: Mothers of advanced maternal age (AMA) at childbirth (age ‡35 years) may have different perceptions of autism spectrum disorder (ASD) risk, independent of sociodemographic factors, that may affect ASD identification. We aimed to estimate associations between AMA and both age of a child's first evaluation noting developmental concerns and time from first evaluation to first ASD diagnosis. Methods: We used data for 8-year-olds identified with ASD in the 2008 to 2012 Autism and Developmental Disabilities Monitoring Network. We estimated differences in age at first evaluation noting developmental concerns and time to first ASD diagnosis by AMA using quantile and Cox regression. Results: Of 10,358 children with ASD, 19.7% had mothers of AMA. AMA was associated with higher educational attainment and previous live births compared with younger mothers. In unadjusted analyses, AMA was associated with earlier first evaluation noting developmental concerns (median 37 vs 40 mo) and patterns in time to first evaluation (hazard ratio: 1.12, 95% confidence interval: 1.06-1.18). Associations between AMA and evaluation timing diminished and were no longer significant after adjustment for socioeconomic and demographic characteristics. Children's intellectual disability did not modify associations between AMA and timing of evaluations. Conclusion: Advanced maternal age is a sociodemographic factor associated with younger age of first evaluation noting developmental concerns in children with ASD, but AMA was not independently associated likely, because it is a consequence or cofactor of maternal education and other sociodemographic characteristics. AMA may be a demographic factor to consider when aiming to screen and evaluate children at risk for ASD

    Findings from a couple-based open trial for adult anorexia nervosa

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    Adult anorexia nervosa (AN) often is persistent, significantly erodes quality of life for both the patient and loved ones, and carries high medical and psychiatric comorbidity. Whereas individual psychotherapy for adult AN leads to improvement in some patients, recent findings indicate that the magnitude of improvement is limited: Only a small percentage of individuals fully recover and dropout rates are high. Thus, it is important to build upon current interventions to improve treatment response. We present results from an open trial of a couple-based intervention for adult anorexia nervosa as an adjunct treatment to standard multidisciplinary care. Twenty couples received treatment over approximately 26 weeks, including a couple-based intervention, individual CBT sessions, psychiatry visits for medication management, and nutritional counseling sessions. The results indicate that patients improved at posttest and 3-month follow-up on a variety of AN-related measures, anxiety and depression, and relationship adjustment. Partners also improved on anxiety, depression, and relationship adjustment. In an exploratory analysis, the multicomponent couple treatment intervention was benchmarked to well-conducted randomized controlled trials of individual therapy for AN; the couple intervention seems to compare favorably on AN-related measures and was associated with a lower dropout rate. In spite of methodological limitations, the findings suggest that including partners in the treatment of adult AN holds potential for bolstering treatment outcomes

    The Association between Symptom Accommodation and Emotional Coregulation in Couples with Binge Eating Disorder

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    Intense negative emotions and maladaptive behavioral strategies to reduce emotional distress occur not only in patients with various forms of psychopathology but also in their committed partners. One common strategy to reduce distress is for partners to accommodate to the symptoms of the disorder, which reduces distress short term but maintains symptoms long term. Accommodation is believed to be motivated by the partner reacting behaviorally to the patient's emotions, but the emotions of the partner in this context have yet to be examined. This pilot study examined how partner accommodation related to specific patterns of emotional coregulation between patients with binge eating disorder (BED) and their partners, before and after a couple-based intervention for BED. Vocally encoded emotional arousal was measured during couples’ (n = 11) conversations about BED. As predicted, partners’ emotional reactivity to patients’ emotional arousal was associated with high accommodation before treatment. Thus, partners may use accommodation as a strategy to reduce both the patients’ and their own distress. After treatment, partners’ arousal was no longer associated with the patients’ emotional arousal; instead, partners showed greater emotional stability over time, specifically when accommodation was low. Additionally, patients were less emotionally aroused after treatment. Therefore, treatment may have decreased overall emotionality of patients and altered the association between accommodation and partners’ emotional reactivity. If replicated, this understanding of the emotional context associated with accommodation in BED can inform couple-based treatment by targeting specific emotional precipitants of behaviors that maintain symptoms

    Incision history of the Black Canyon of Gunnison, Colorado, over the past ~1 Ma inferred from dating of fluvial gravel deposits

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    Spatio-temporal variability in fluvial incision rates in bedrock channels provides data regarding uplift and denudation histories of landscapes. The longitudinal profi le of the Gunnison River (Colorado), tributary to the Colorado River, contains a prominent knickzone with 800 m of relief across it within the Black Canyon of the Gunnison. Average bedrock incision rates over the last 0.64 Ma surrounding the knickpoint vary from 150 m/Ma (downstream) to 400-550 m/Ma (within) to 90-95 m/Ma (upstream), suggesting it is a transient feature. Lava Creek B ash constrains strath terraces along a paleoprofi le of the river. An isochron cosmogenic burial date in the paleo-Bostwick River of 870 ± 220 ka is consistent with the presence of 0.64 Ma Lava Creek B ash in locally derived, stratigraphically younger sediment. With 350 m of incision since deposition, we determine an incision rate of 400-550 m/Ma, reflecting incision through resistant basement rock at 2-3 times regional incision rates. Such contrast is attributed to a wave of transient incision, potentially initiated by downstream base-level fall during abandonment of Unaweep Canyon at ca. 1 Ma. Rate extrapolation indicates that the ~700 m depth of Black Canyon has been eroded since 1.3-1.75 Ma. The Black Canyon knickpoint overlies a strong gradient between low-velocity mantle under the Colorado Rockies and higher-velocity mantle of the Colorado Plateau. We interpret recent reorganization and transient incision of both the Gunnison River and upper Colorado River systems to be a response to mantle-driven epeirogenic uplift of the southern Rockies in the last 10 Ma

    A pilot open trial of UNITE-BED: A couple-based intervention for binge-eating disorder

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    Objective: To evaluate the feasibility, acceptability, and preliminary efficacy of a couple-based intervention for binge-eating disorder (BED), called UNiting couples In the Treatment of Eating disorders-BED edition (UNITE-BED). Method: In an open pilot trial, 11 couples in which one or both adult partners had a diagnosis of DSM-5 threshold or sub-threshold BED participated in 22 weekly sessions of UNITE-BED. Patients also received individual treatment, outside of the context of the trial. Couples completed measures on treatment satisfaction, eating disorder symptom severity, depression, anxiety, emotion regulation, and relational functioning at post-treatment and 3-month follow-up. Statistical analyses were conducted to identify change over the course of treatment. Results: UNITE was feasible and acceptable to the majority of couples (9% dropout; high satisfaction ratings). Objective binge abstinence was 81.8% and subjective binge abstinence was 45.5% by post-treatment. Patient binge-eating symptomatology reduced over the course of treatment with results maintained at follow up. Patients' depression symptoms decreased and patients' emotion regulation improved at both time points. Discussion: Including partners in treatment for BED may be beneficial. Results support further evaluation of the efficacy of couple-based interventions for BED in larger randomized-controlled trials

    Abandonment of Unaweep Canyon (1.4-0.8 Ma), western Colorado: Effects of stream capture and anomalously rapid Pleistocene river incision

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    Cosmogenic-burial and U-series dating, identification of fluvial terraces and lacustrine deposits, and river profile reconstructions show that capture of the Gunnison River by the Colorado River and abandonment of Unaweep Canyon (Colorado, USA) occurred between 1.4 and 0.8 Ma. This event led to a rapid pulse of incision unlike any documented in the Rocky Mountains. Following abandonment of Unaweep Canyon by the ancestral Gunnison River, a wave of incision propagated upvalley rapidly through Mancos Shale at rates of ̃90-440 km/m.y. The Gunnison River removed 400-500 km3 of erodible Mancos Shale and incised as deep as 360 m in 0.17-0.76 m.y. (incision rates of ̃470-2250 m/m.y.). Prior to canyon abandonment, long-term (ca. 11-1 Ma) Gunnison River incision averaged ̃100 m/m.y. The wave of incision also caused the subsequent capture of the Bostwick-Shinn Park River by the ancestral Uncompahgre River ca. 0.87-0.64 Ma, at a location ̃70 km upvalley from Unaweep Canyon. This event led to similarly rapid (to ̃500 m/m.y.) but localized river incision. As regional river incision progressed, the juxtaposition of resistant Precambrian bedrock and erodible Mancos Shale within watersheds favored the development of significant relief between adjacent stream segments, which led to stream piracy. The response of rivers to the abandonment of Unaweep Canyon illustrates how the mode and tempo of long-term fluvial incision are punctuated by short-term geomorphic events such as stream piracy. These shortterm events can trigger significant landscape changes, but the effects are more localized relative to regional climatically or tectonically driven events
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