2,800 research outputs found
Life Cycle Assessment of Bioplastics and Food Waste Disposal Methods
The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management
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Central endoscopy reads in inflammatory bowel disease clinical trials: The role of the imaging core lab
Clinical trials in inflammatory bowel disease (IBD) are evolving at a rapid pace by employing central reading for endoscopic mucosal assessment in a field that was, historically, largely based on assessments by local physicians. This transition from local to central reading carries with it numerous technical, operational, and scientific challenges, many of which can be resolved by imaging core laboratories (ICLs), a concept that has a longer history in clinical trials in a number of diseases outside the realm of gastroenterology. For IBD trials, ICLs have the dual goals of providing objective, consistent assessments of endoscopic findings using central-reading paradigms whilst providing important expertise with regard to operational issues and regulatory expectations. This review focuses on current approaches to using ICLs for central endoscopic reading in IBD trials
A Mesoscopic Simulation Model for Airport Curbside Management
Airport curbside congestion is a growing problem as airport passenger traffic continues to increase. Many airports accommodate the increase in passenger traffic by relying on policy and design measures to alleviate congestion and optimize operations. This paper presents a mesoscopic simulation model to assess the effectiveness of such policies. The mesoscopic simulation model combines elements of both microscopic simulation which provides a high level of detail but requires large amounts of data and macroscopic simulation which requires very little data but provides few performance measures. The model is used to simulate scenarios such as double parking, alternative parking space allocation, increased passenger demand, and enforced dwell times at Pearson International Airport in Toronto, Canada. Scenario analysis shows that adjusting model inputs provides reasonable results, demonstrating the value in using this approach to evaluate curbside management policies. The results show that double parking reduces the utilization ratio and the level of service of the outer curbside but cuts down the passenger and vehicle waiting time. Inclement weather conditions reduce the utilization ratio of the inner curbside and the supply of commercial vehicles since it takes them longer to return to the airport. Finally, reducing the allowable parking time at the curbside decreases the average dwell time of private vehicles from 89 seconds to 75 seconds but increases the number of circulating vehicles by 30%
首都圏外郭放水路の洪水被害軽減効果
Cooling is a mainstay of burns first aid, with clinically-proven benefits, but the mechanism remains unclear. Aims To identify significant changes in the proteome of normal human skin from burning and the effect of cooling on these changes using our validated human burn model
Magnetoresistance of YBa2Cu3O7 in the "cold spots" model
We calculate the in-plane magnetoresistance of
YBaCuO in a magnetic field applied perpendicular to the
planes for the ``cold spots'' model. In this model, the electron relaxation
time at small regions on the Fermi surface near the
Brillouin zone diagonals is much longer than the relaxation time
at the rest of the Fermi surface ( is temperature). In
qualitative agreement with the experiment, we find that Kohler's rule is
strongly violated, but the ratio ,
where is the Hall angle, is approximately
temperature-independent. We find the ratio is about 5.5, which is of the same
order of magnitude as in the experiment.Comment: RevTeX, 4 pages, 6 figures. V.2: 2 references adde
Magnetoresistance in High-Tc Superconductors: The Role of Vertex Corrections
In high-Tc cuprates, the orbital magnetoresistance in plane (MR,
) is anomalously enhanced at lower tempemeratures compared
with conventional Fermi liquids, and thus Kohler's rule is strongly violated.
Moreover, it should be noted that an intimate relation between the MR and the
Hall coefficient (), , holds well
experimentally, and is called the "modified Kohler's rule". In this letter, we
study this long-standing problem in terms of the nearly antiferromagnetic (AF)
Fermi liquid. We analyze the exact expression for the MR by including the
vertex corrections (VC's) to keep the conservation laws, and find the
approximate "scaling relation"
( being the AF correlation length.) in the presence of AF
fluctuations. The factor , which comes from the VC's for the
current, gives the additional temperature dependence. By taking account of the
relation [Kontani et al., PRB 59 (1999) 14723.], we
can naturally explain the modified Kohler's rule. In conclusion, based on the
Fermi liquid theory, the famous {\it seemingly} non-Fermi liquid behaviors of
the Hall coefficient and the MR in high-Tc cuprates are naturally understood on
an equal footing.Comment: 5 pages, 5 figures, to appear in J. Phys. Soc. Jpn. 70 (2001) No.
Changes in the movement and calling behavior of minke whales (Balaenoptera acutorostrata) in response to navy training
This research was funded by the U.S. Office of Naval Research under grant number N000141612859. The passive acoustic data were recorded under support by COMPACFLT for the Navy Marine Species Monitoring Program. The call association tracking algorithm was developed under a separate U.S. Office of Naval Research project (2011–2015 Advanced Detection, Classification and Localization, grant number: N0001414IP20037).Many marine mammals rely on sound for foraging, maintaining group cohesion, navigation, finding mates, and avoiding predators. These behaviors are potentially disrupted by anthropogenic noise. Behavioral responses to sonar have been observed in a number of baleen whale species but relatively little is known about the responses of minke whales (Balaenoptera acutorostrata). Previous analyses demonstrated a spatial redistribution of localizations derived from passive acoustic detections in response to sonar activity, but the lack of a mechanism for associating localizations prevented discriminating between movement and cessation of calling as possible explanations for this redistribution. Here we extend previous analyses by including an association mechanism, allowing us to differentiate between movement responses and calling responses, and to provide direct evidence of horizontal avoidance responses by individual minke whales to sonar during U.S. Navy training activities. We fitted hidden Markov models to 627 tracks that were reconstructed from 3 years of minke whale (B. acutorostrata) vocalizations recorded before, during, and after naval training events at the U.S. Navy's Pacific Missile Range Facility, Kauai, Hawaii. The fitted models were used to identify different movement behaviors and to investigate the effect of sonar activity on these behaviors. Movement was faster and more directed during sonar exposure than in baseline phases. The mean direction of movement differed during sonar exposure, and was consistent with movement away from sonar-producing ships. Animals were also more likely to cease calling during sonar. There was substantial individual variation in response. Our findings add large-sample support to previous demonstrations of horizontal avoidance responses by individual minke whales to sonar in controlled exposure experiments, and demonstrate the complex nature of behavioral responses to sonar activity: some, but not all, whales exhibited behavioral changes, which took the form of horizontal avoidance or ceasing to call.Publisher PDFPeer reviewe
Evaluation of marking of peer marking in oral presentation.
BACKGROUND: Peer marking is an important skill for students, helping them to understand the process of learning and assessment. This method is increasingly used in medical education, particularly in formative assessment. However, the use of peer marking in summative assessment is not widely adopted because many teachers are concerned about biased marking by students of their peers. OBJECTIVE: The aim of this study was to investigate whether marking of summative peer assessment can improve the reliability of peer marking. METHODS: In a retrospective analysis, the peer-marking results of a summative assessment of oral presentations of two cohorts of students were compared. One group of students was told that their peer marks would be assessed against a benchmark consisting of the average of examiner marks and that these scores together with the peer and examiner marks would form their final exam results. The other group of students were just informed that their final exam results would be determined based on the examiner and peer marks. RESULTS: Based on examiner marks, both groups of students performed similarly in their summative assessment, agreement between student markers was less consistent and more polar than the examiners. When compared with the examiners, students who were told that their peer marking would be scored were more generous markers (their average peer mark was 2.4 % points higher than the average examiner mark) while students who were not being scored on their marking were rather harsh markers (their average peer mark was 4.2 % points lower than the average examiner mark), with scoring of the top-performing students most affected. CONCLUSIONS: Marking of peer marking had a small effect on the marking conduct of students in summative assessment of oral presentation but possibly indicated a more balanced marking performance
Magnetotransport in the Normal State of La1.85Sr0.15Cu(1-y)Zn(y)O4 Films
We have studied the magnetotransport properties in the normal state for a
series of La1.85Sr0.15Cu(1-y)Zn(y)O4 films with values of y, between 0 and
0.12. A variable degree of compressive or tensile strain results from the
lattice mismatch between the substrate and the film, and affects the transport
properties differently from the influence of the zinc impurities. In
particular, the orbital magnetoresistance (OMR) varies with y but is
strain-independent. The relations for the resistivity and the Hall angle and
the proportionality between the OMR and tan^2 theta are followed about 70 K. We
have been able to separate the strain and impurity effects by rewriting the
above relations, where each term is strain-independent and depends on y only.
We also find that changes in the lattice constants give rise to closely the
same fractional changes in other terms of the equation.The OMR is more strongly
supressed by the addition of impurities than tan^2 theta. We conclude that the
relaxation ratethat governs Hall effect is not the same as for the
magnetoresistance. We also suggest a correspondence between the transport
properties and the opening of the pseudogap at a temperature which changes when
the La-sr ratio changes, but does not change with the addition of the zinc
impurities
Feminizing effects of ethinylestradiol in roach (Rutilus rutilus) populations with different estrogenic pollution exposure histories
This is the final version. Available on open access from Elsevier via the DOI in this record. Experimental exposures aimed at assessing the risks posed by estrogens in waste-water treatment work (WwTW)
effluents to fish populations have rarely considered whether populations differ in their sensitivity to estrogenic
compounds. This is despite evidence that selection at genes involved in the estrogen response has occurred in
wild populations, and evidence that genotype can influence estrogen-response. In this study we compare the
effects of a two-year exposure to a low measured concentration (1.3 ng/L) of ethinylestradiol (EE2) on the sexual
development of roach (Rutilus rutilus) whose parental generation was sampled from two river stretches heavily
contaminated with WwTW effluent and from two without any known WwTW effluent contamination. Exposure
to EE2 significantly reduced the proportion of genetic males and induced a range of feminized phenotypes in
males. Significantly, exposure also increased the proportion of genetic females with vitellogenic oocytes from 51
to 96%, raising the possibility that estrogen pollution could impact populations of annually spawning fish species
through advancing female reproduction by at least a year. However, there was no evidence that river origin
affected sensitivity to estrogens in either sex. Thus, we conclude that chronic exposure to low level EE2 has
reproductive health outcomes for both male and female roach, but we find no evidence that the nature or
magnitude of the response is affected by the population origin.Natural Environment Research Counci
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