77 research outputs found

    Developing Landsat Based Algorithms To Augment In Situ Monitoring Of Freshwater Lakes And Reservoirs

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    Many lakes and reservoirs lack adequate water quality monitoring programs. With little information on the state of these systems, managing these resources and their contributing watersheds is a challenge. The use of remote sensing presents an opportunity to better characterize these freshwater systems. The full potential of using the Landsat program to measure optically active water quality parameters, such as chlorophyll-a, suspended sediments and water clarity was explored using the Qaraoun Reservoir in Lebanon as a case study. An in situ monitoring program was developed and synchronized with the overpass of Landsat 7 and the newly launched Landsat 8 satellites in an effort to develop, calibrate, and validate empirical relationships that link water quality parameters with sensor radiances. Collected monitoring data revealed that the reservoir was hypereutrophic, with median summer chlorophyll-a concentrations exceeding 70 ug/L. The generated models showed promise in capturing the state of the reservoir, with some differences between the models developed for Landsat 7 and 8. These differences are expected to have implications on the transferability of the developed algorithms and on blending data from both satellites. Yet, the results highlight the importance of using the Landsat program as part of future monitoring activities as well as for hindcasting surface water quality, both a key step towards tracking changes in the system over time

    Developing A Hydrologic Information System: Towards Promoting Sustainable Standardization

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    Water quantity and quality monitoring plays a key role towards the development of a sustainable water sector. The required infrastructure needed to monitor and manage surface and groundwater systems are often lacking particularly in developing countries. When available, water quantity and quality data are invariably fragmented, intermittent, not shared, with deficient metadata, and stored in formats that hinder establishing seamless coupling with hydrological models. Most data are saved locally with little attention placed on defining and maintaining metadata on the collection protocols, geographic referencing, measurement accuracy, resolution, detection limits, and data censorship. These limitations present serious challenges in reaching sound water management strategies. To alleviate these shortcomings, a Hydrologic Information System (HIS) based on the ArcHydro data model was developed using the country of Lebanon as a prototype. The HIS centralized available hydrological and water resources information; coupled spatial coverage with respective time series data on flow, water demand, meteorology, and water quality; and standardized metadata. Additionally, the system was structured to support hydrologic modeling and water resources analysis. A loose coupling was also integrated between the system and the Water Evaluation And Planning (WEAP) hydrological model and tested on the Upper Litani River Basin. The framework encompassed the ability to export back model simulation results and incorporate them within the HIS as time series records. The developed HIS system has since been adopted as a data repository for other water related projects in Lebanon and has helped identify key gaps in existing data and set monitoring priorities

    Potential of heat pipe technology in nuclear seawater desalination

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    The official published version of this article can be found at the link below.Heat pipe technology may play a decisive role in improving the overall economics, and public perception on nuclear desalination, specifically on seawater desalination. When coupled to the Low-Temperature Multi-Effect Distillation process, heat pipes could effectively harness most of the waste heat generated in various types of nuclear power reactors. Indeed, the potential application of heat pipes could be seen as a viable option to nuclear seawater desalination where the efficiency to harness waste heat might not only be enhanced to produce larger quantities of potable water, but also to reduce the environmental impact of nuclear desalination process. Furthermore, the use of heat pipe-based heat recovery systems in desalination plant may improve the overall thermodynamics of the desalination process, as well as help to ensure that the product water is free from any contamination which occur under normal process, thus preventing operational failure occurrences as this would add an extra loop preventing direct contact between radiation and the produced water. In this paper, a new concept for nuclear desalination system based on heat pipe technology is introduced and the anticipated reduction in the tritium level resulting from the use of heat pipe systems is discussed

    Evaluation of the effectiveness of sleep hygiene education and FITBIT devices on quality of sleep and psychological worry: a pilot quasi-experimental study among first-year college students

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    BackgroundCollege students report disturbed sleep patterns that can negatively impact their wellbeing and academic performance.ObjectivesThis study examined the effect of a 4-week sleep hygiene program that included sleep education and actigraph sleep trackers (FITBITs) on improving sleep quality and reducing psychological worry without control group.Design, settings, and participantsA pilot quasi-experimental design, participants were randomly selected medical and health sciences from a university students in the United-Arab-Emirates.MethodsStudents were asked to wear FITBITs and log their daily sleep data and completed the Pittsburgh Sleep Quality Index (PSQI) and Penn State Worry Questionnaire (PSWQ). Extensive sleep hygiene education was delivered via lectures, a WhatsApp group, and the Blackboard platform. In total, 50 students completed pre-and post-assessments and returned FITBIT data.ResultsThere was a significant difference in the prevalence of good sleep postintervention compared with pre-intervention (46% vs. 28%; p = 0.0126). The mean PSQI score was significantly lower post-intervention compared with pre-intervention (6.17 ± 3.16 vs. 7.12.87; p = 0.04, Cohen’s d 0.33). After the intervention, subjective sleep quality, sleep latency, and daytime dysfunction were significantly improved compared with pre-intervention (p < 0.05). In addition, FITBIT data showed total sleep time and the number of restless episodes per night were significantly improved postintervention compared with pre-intervention (p = 0.013). The mean PSWQ score significantly decreased from pre-intervention to p = 0.049, Cohen’ d = 0.25. The correlation between PSQI and PSWQ scores was significant post-intervention (β = 0.40, p = 0.02).ConclusionOur results may inform university educational policy and curricular reform to incorporate sleep hygiene awareness programs to empower students and improve their sleep habits

    In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

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    The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

    TXS 0506+056 with Updated IceCube Data

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    Past results from the IceCube Collaboration have suggested that the blazar TXS 0506+056 is a potential source of astrophysical neutrinos. However, in the years since there have been numerous updates to event processing and reconstruction, as well as improvements to the statistical methods used to search for astrophysical neutrino sources. These improvements in combination with additional years of data have resulted in the identification of NGC 1068 as a second neutrino source candidate. This talk will re-examine time-dependent neutrino emission from TXS 0506+056 using the most recent northern-sky data sample that was used in the analysis of NGC 1068. The results of using this updated data sample to obtain a significance and flux fit for the 2014 TXS 0506+056 "untriggered" neutrino flare are reported

    Searches for IceCube Neutrinos Coincident with Gravitational Wave Events

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    Conditional normalizing flows for IceCube event reconstruction

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    Galactic Core-Collapse Supernovae at IceCube: “Fire Drill” Data Challenges and follow-up

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    The next Galactic core-collapse supernova (CCSN) presents a once-in-a-lifetime opportunity to make astrophysical measurements using neutrinos, gravitational waves, and electromagnetic radiation. CCSNe local to the Milky Way are extremely rare, so it is paramount that detectors are prepared to observe the signal when it arrives. The IceCube Neutrino Observatory, a gigaton water Cherenkov detector below the South Pole, is sensitive to the burst of neutrinos released by a Galactic CCSN at a level >10σ. This burst of neutrinos precedes optical emission by hours to days, enabling neutrinos to serve as an early warning for follow-up observation. IceCube\u27s detection capabilities make it a cornerstone of the global network of neutrino detectors monitoring for Galactic CCSNe, the SuperNova Early Warning System (SNEWS 2.0). In this contribution, we describe IceCube\u27s sensitivity to Galactic CCSNe and strategies for operational readiness, including "fire drill" data challenges. We also discuss coordination with SNEWS 2.0
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