2,506 research outputs found
Moving from Probabilistic to Time-Based On-Time Performance (for practitioners)
On-Time Performance (OTP) is a probabilistic measure that tells the customer the likelihood that the trip they are about to take will arrive on-time. However, this metric forces the customer to think in terms of a probability of trip timeliness and not an actual time value for how timely the trip will be. This presentation will explore a new way to examine on-time performance by quantifying the timeliness of trips. Customers can then use this information to determine which trip would be the best to take based on when they need to arrive at their destination. Using a system science approach, this new method will take into consideration the impact of service disruptions, reroutes, service failures, and other factors on the timeliness of route trips. This metric is especially important for customers who are attempting to make connections that hinge on reliable and timely travel times.https://pdxscholar.library.pdx.edu/trec_seminar/1236/thumbnail.jp
Influence of organic films on the evaporation and condensation of water in aerosol
Uncertainties in quantifying the kinetics of evaporation and condensation of water from atmospheric aerosol are a significant contributor to the uncertainty in predicting cloud droplet number and the indirect effect of aerosols on climate. The influence of aerosol particle surface composition, particularly the impact of surface active organic films, on the condensation and evaporation coefficients remains ambiguous. Here, we report measurements of the influence of organic films on the evaporation and condensation of water from aerosol particles. Significant reductions in the evaporation coefficient are shown to result when condensed films are formed by monolayers of long-chain alcohols [C(n)H((2n+1))OH], with the value decreasing from 2.4 × 10(−3) to 1.7 × 10(−5) as n increases from 12 to 17. Temperature-dependent measurements confirm that a condensed film of long-range order must be formed to suppress the evaporation coefficient below 0.05. The condensation of water on a droplet coated in a condensed film is shown to be fast, with strong coherence of the long-chain alcohol molecules leading to islanding as the water droplet grows, opening up broad areas of uncoated surface on which water can condense rapidly. We conclude that multicomponent composition of organic films on the surface of atmospheric aerosol particles is likely to preclude the formation of condensed films and that the kinetics of water condensation during the activation of aerosol to form cloud droplets is likely to remain rapid
Factors influencing ownership, tenancy, mobility and use of farmland in the United Kingdom. Information on agriculture 74, 1980
Laboratory Evaluation of Crack and Crevice Treatments for Control of the German Cockroach, Blatella Germanica (Linneaus), Using Various Nozzle Types, Nozzle Heights, and Crack Widths
Entomolog
Computer simulation of light propagation through a scattering medium.
http://archive.org/details/computersimulati00mil
Identity Development of Adolescent Gay Black Males
During adolescence, self-identified gay black males may develop their identities differently than their gay white male counterparts. This may be attributed to the reconciliation of stressors when developing gay, black, and male identities within certain environmental contexts. To investigate this, twelve qualitative interviews were conducted of gay black males from which developmental themes were extracted. While many of the developmental processes are similar to their white homosexual counterparts, some differences were noted regarding racism, objectification by the white gay community, and use of the internet to develop particular identities. A new theory using dynamic systems theory that includes many complexities of identity development is proposed. A hybrid story-like model was developed to illustrate the roles of lenses and buffers as they pertain to how an identity functions. Lenses allow a person to see their way through a variety of experiences; buffers contain coping mechanisms and skills to alleviate tension from negative experiences. Future research should include other minority groups and women for a more complete picture of identity development processes. This would allow better tools to be built that can be utilized by intervention designers
The psychological wellbeing outcomes of nonpharmacological interventions for older persons with insomnia symptoms: a systematic review and meta-analysis
Nonpharmacological treatment of insomnia in older persons has been associated with reduced insomnia symptoms and increased psychological wellbeing. This systematic review and meta-analysis examined whether nonpharmacological interventions can promote wellbeing indicators in older persons who experience insomnia symptoms and investigated the components of these interventions. Twenty studies met inclusion criteria. Psychological wellbeing outcomes included symptoms of depression, anxiety, mental health-related quality of life, and fatigue. Interventions significantly reduced depression and fatigue symptoms in most of the studies that included these outcomes. Findings of our qualitative analysis suggest that mindfulness-based interventions in particularcan potentially reduce depression symptoms in older persons with insomnia symptoms. Meta-analyses of studies that included psychological wellbeing outcomes showed small-medium weighted mean effects indicating reductions in symptoms of depression, anxiety, and fatigue. The results suggest that nonpharmacological interventions for older persons with insomnia symptoms can potentially reduce depression and fatigue symptoms and highlight interventions that may be particularly valuable for this purpose
Chewing gum benefits sustained attention in the absence of task degradation.
OBJECTIVES: The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. METHODS: In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. RESULTS: Chewing gum was associated with improved attentional task performance. This finding was not contingent upon a general decrease in attentional performance and was apparent at all stages of the task. Subjective measures of alertness, contentedness, and calmness were higher following the chewing of gum. Changes in sustained attention co-varied with subjective alertness. DISCUSSION: The effects of chewing gum on attention and alertness are consistent with past literature and were not contingent on declines in attention. Additionally, we found evidence that gum-induced changes in self-rated alertness and attention are related. We found no support for the proposition that chewing gum can impair attention due to the division of resources
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