321 resultados para Sixty-minute isotherm
Resumo:
Objective: We aimed to assess the impact of task demands and individual characteristics on threat detection in baggage screeners. Background: Airport security staff work under time constraints to ensure optimal threat detection. Understanding the impact of individual characteristics and task demands on performance is vital to ensure accurate threat detection. Method: We examined threat detection in baggage screeners as a function of event rate (i.e., number of bags per minute) and time on task across 4 months. We measured performance in terms of the accuracy of detection of Fictitious Threat Items (FTIs) randomly superimposed on X-ray images of real passenger bags. Results: Analyses of the percentage of correct FTI identifications (hits) show that longer shifts with high baggage throughput result in worse threat detection. Importantly, these significant performance decrements emerge within the first 10 min of these busy screening shifts only. Conclusion: Longer shift lengths, especially when combined with high baggage throughput, increase the likelihood that threats go undetected. Application: Shorter shift rotations, although perhaps difficult to implement during busy screening periods, would ensure more consistently high vigilance in baggage screeners and, therefore, optimal threat detection and passenger safety.
Resumo:
Nanoconfined synthesized crystalline fullerene mesoporous carbon (C60-FMC) with bimodal pore architectures of 4.95 nm and 10-15 nm pore sizes characterized by XRD, TEM, nitrogen adsorption/ desorption isotherm and solid-state NMR, and the material was used for protein immobilization. The solid-state 13C NMR spectrum of C60-FMC along with XRD, BET and TEM confirms the formation of fullerene mesoporous carbon structure C60-FMC. The immobilization of albumin (from bovine serum, BSA) protein biomolecule in a buffer solution at pH 4.7 was used to determine the adsorption properties of the C60-FMC material and its structural changes investigated by FT-IR. We demonstrated that the C60-FMC with high surface area and pore volumes have excellent adsorption capacity towards BSA protein molecule. Protein adsorption experiments clearly showed that the C60-FMC with bimodal pore architectures (4.95 nm and 10-15 nm) are suitable material to be used for protein adsorption
Resumo:
Highly ordered mesoporous carbon (MC) has been synthesized from sucrose, a non-toxic and costeffective source of carbon. X-ray diffraction, N2 adsorption–desorption isotherm and transmission electron micrograph (TEM) were used to characterize the MC. The XRD patterns show the formation of highly ordered mesoporous structures of SBA15 and mesoporous carbon. The N2 adsorptiondesorption isotherms suggest that the MC exhibits a narrow pore-size distribution with high surface area of 1559 m2/g. The potential application of MC as a novel electrode material was investigated using cyclic voltammetry for riboflavin (vitamin B2) and dopamine. MC-modified glassy carbon electrode (MC/GC) shows increase in peak current compared to GC electrode in potassium ferricyanide which clearly suggest that MC/GC possesses larger electrode area (1.8 fold) compared with bare GC electrode. The electrocatalytic behavior of MC/GC was investigated towards the oxidation of riboflavin (vitamin B2) and dopamine using cyclic voltammetry which show larger oxidation current compared to unmodified electrode and thus MC/GC may have the potential to be used as a chemically modified electrode.
Resumo:
Disengagement from services is common before suicide, hence identifying factors at treatment presentation that predict future suicidality is important. This article explores risk profiles for suicidal ideation among treatment seekers with depression and substance misuse. Participants completed assessments at baseline and 6 months. Baseline demographics, psychiatric history, and current symptoms were entered into a decision tree to predict suicidal ideation at follow-up. Sixty-three percent of participants at baseline and 43.5% at follow-up reported suicidal ideation. Baseline ideation most salient when psychiatric illness began before adulthood, increasing the rate of follow-up ideation by 16%. Among those without baseline ideation, dysfunctional attitudes were the most important risk factor, increasing rates of suicidal ideation by 35%. These findings provide evidence of factors beyond initial diagnoses that increase the likelihood of suicidal ideation and are worthy of clinical attention. In particular, providing suicide prevention resources to those with high dysfunctional attitudes may be beneficial.
Resumo:
Vampire bats, Desmodus rotundus, must maximize their feeding cycle of one blood meal per day by being efficient in the stalking and acquisition of their food. Riskin and Hermanson documented the running gait of the common vampire bat and observed they were efficient at running speeds, using longer stride lengths and thus decreased stride frequency. We obtained preliminary data on gait maintained for up to 10 minutes on a moving treadmill belt at speeds ranging from 0.23 to 0.74 m/s, which spanned a range from walking to running gaits. Bats tended to transition between gaits at about 0.40 m/s. Fourteen bats were studied and included four that were able to walk or run for 10 minutes. There was no significant change in either stride duration or frequency associated with an increase in speed. We estimated O2 consumption and CO2 production both before and 5 minutes after exercise, and found that O2 consumption increased 1 minute and 5 minutes after exercise. CO2 levels increased significantly 1 minute after exercise, but tended back towards pre-exercise level 5 minutes after exercise. Two bats were tested for blood O2, CO2 and pH levels. Interestingly, pH levels fell from 7.3 to about 7.0, indicating lactate accumulation.
Resumo:
A diversity of programs oriented to young people seek to develop their capacities and their connection to the communities in which they live. Some focus on ameliorating a particular issue or ‘deficit’ whilst others, such as sporting, recreation and youth groups are more grounded in the community. This article reports a qualitative study undertaken in three remote Indigenous communities in Central Australia. Sixty interviews were conducted with a range of stakeholders involved in a diversity of youth programs. A range of critical challenges for and characteristics of remote Indigenous youth programs are identified if such programs are to be ‘fit for context’. ‘Youth centred-context specific’ provides a positive frame for the delivery of youth programs in remote Central Australia, encouraging an explicit focus on program logic; program content and processes; and relational, temporal, and, spatial aspects of the practice context. These provide lenses with which youth program planning and delivery may be enhanced in remote communities. Culturally safe service planning and delivery suggests locally determined processes for decision-making and community ownership. In some cases, this may mean a community preference for all ages to access the service to engage in culturally relevant activities. Where activities are targeted at young people, yet open to and inclusive of all ages, they provide a medium for cross-generational interaction that requires a high degree of flexibility on the part of staff and funding programs. Although the findings are focused in Central Australia, they may be relevant to similar contexts elsewhere.