66 research outputs found
Ultrasound enhancement of microfiltration performance for natural organic matter removal
Sonication of water at 1500 W power prior to microfiltration showed that short sonication times (60 s) gave a reduced flux decline. It is suggested that a less potent, smaller molecular form of the natural organic matter (NOM) was produced by sonication. Longer sonication times diminished this beneficial effect. This may be due to the formation of aggregates or compounds that are more readily adsorbed on the membrane. Where the sonication was preceded by an alum treatment, the flux loss showed a regular decrease with longer sonication times. It is suggested that the effects of sonication on the alum flocs and on the flocs; NOM interactions may play a critical role in regulating the flux. Where sand was present on sonication at 800 and 1400 W, the cavitational energy was focussed on adsorbed organic material, resulting in more efficient destruction and the formation of compounds that counteracted the flux enhancement
Natural gauge mediation with a bino NLSP at the LHC
Natural models of supersymmetry with a gravitino LSP provide distinctive
signatures at the LHC. For a neutralino NLSP, sparticles can decay to two high
energy photons plus missing energy. We use the ATLAS diphoton search with 4.8
fb^{-1} of data to place limits in both the stop-gluino and neutralino-chargino
mass planes for this scenario. If the neutralino is heavier than 50 GeV, the
lightest stop must be heavier than 580 GeV, the gluino heavier than 1100 GeV
and charginos must be heavier than approximately 300-470 GeV. This provides the
first nontrivial constraints in natural gauge mediation models with a
neutralino NLSP decaying to photons, and implies a fine tuning of at least a
few percent in such models.Comment: 10 pages, 3 figures; v2: updated figure 3, version published in PR
A scalable approach to legal question answering
Lexis Answers is a question answering service deployed within a live production system. In this paper we provide an overview of the system, an insight into some of the key AI challenges, and a brief description of current evaluation techniques
Electronic transport and device prospects of monolayer molybdenum disulphide grown by chemical vapour deposition
Layered transition metal dichalcogenides display a wide range of attractive
physical and chemical properties and are potentially important for various
device applications. Here we report the electronic transport and device
properties of monolayer molybdenum disulphide (MoS2) grown by chemical vapour
deposition (CVD). We show that these devices have the potential to suppress
short channel effects and have high critical breakdown electric field. However,
our study reveals that the electronic properties of these devices are at
present, severely limited by the presence of a significant amount of band tail
trapping states. Through capacitance and ac conductance measurements, we
systematically quantify the density-of-states and response time of these
states. Due to the large amount of trapped charges, the measured effective
mobility also leads to a large underestimation of the true band mobility and
the potential of the material. Continual engineering efforts on improving the
sample quality are needed for its potential applications.Comment: 23 pages, 5 figure
Hospital specialist palliative care team influence on end-of-life care in Coronavirus disease 2019? A retrospective observational cohort study
Objectives: The coronavirus 19 disease (COVID-19) pandemic has led to a renewed focus on end-of-life care. The majority of COVID-19 deaths occur in hospital, with patients cared for by generalists and hospital specialist pal- liative care teams (HSPCTs). This project aims at exploring the potential influences of HSPCTs on end-of-life care in COVID-19.
Methods: A retrospective observational study was carried out by exploring four end-of-life care themes in a Scot- tish hospital population who died from COVID-19. Comparison was made between cohorts seen by HSPCTs ver- sus generalist clinicians.
Results: Analysis of 119 patients across NHS Greater Glasgow and Clyde (NHSGGC) health board demonstrated that COVID-19 patients seen by HSPCTs were more likely to be younger (median 77 vs. 81 years; p = 0.02), have a cancer diagnosis (21.7% vs. 5.4%; p = 0.01), die sooner after admission (median four vs. six days; p < 0.01), and be commenced on a syringe driver (89.1% vs. 42.5%; p < 0.01). Differences detected across four end-of-life care themes comparing HSPCTs with generalist teams were minimal with documentation and prescribing in keeping with available guidance.
Conclusion: Consistencies in end-of-life care observed across NHSGGC cohorts draw attention to the potential wider impact of HSPCT roles, including education, guideline development, and mentoring. Understanding such diverse effects is important to support funding and development of HSPCTs. Further research is required to bet- ter quantify the impact and heterogenous influences of HSPCTs in general
A stochastic model for heart rate fluctuations
Normal human heart rate shows complex fluctuations in time, which is natural,
since heart rate is controlled by a large number of different feedback control
loops. These unpredictable fluctuations have been shown to display fractal
dynamics, long-term correlations, and 1/f noise. These characterizations are
statistical and they have been widely studied and used, but much less is known
about the detailed time evolution (dynamics) of the heart rate control
mechanism. Here we show that a simple one-dimensional Langevin-type stochastic
difference equation can accurately model the heart rate fluctuations in a time
scale from minutes to hours. The model consists of a deterministic nonlinear
part and a stochastic part typical to Gaussian noise, and both parts can be
directly determined from the measured heart rate data. Studies of 27 healthy
subjects reveal that in most cases the deterministic part has a form typically
seen in bistable systems: there are two stable fixed points and one unstable
one.Comment: 8 pages in PDF, Revtex style. Added more dat
Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 3 - Design of the Concept Demonstrator
This report provides an outline of the essential features of a Structural Health Monitoring Concept Demonstrator (CD) that will be constructed during the next eight months. It is emphasized that the design cannot be considered to be complete, and that design work will continue in parallel with construction and testing. A major advantage of the modular design is that small modules of the system can be developed, tested and modified before a commitment is made to full system development. The CD is expected to develop and evolve for a number of years after its initial construction. This first stage will, of necessity, be relatively simple and have limited capabilities. Later developments will improve all aspects of the functionality of the system, including sensing, processing, communications, intelligence and response. The report indicates the directions this later development will take
Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 5 - Phase 2 Implementation of the Concept Demonstrator
This report describes the second phase of the implementation of the Concept Demonstrator experimental test-bed system containing sensors and processing hardware distributed throughout the structure, which uses multi-agent algorithms to characterize impacts and determine a suitable response to these impacts. This report expands and adds to the report of the first phase implementation. The current status of the system hardware is that all 192 physical cells (32 on each of the 6 hexagonal prism faces) have been constructed, although only four of these presently contain data-acquisition sub-modules to allow them to acquire sensor data. Impact detection.. location and severity have been successfully demonstrated. The software modules for simulating cells and controlling the test-bed are fully operational. although additional functionality will be added over time. The visualization workstation displays additional diagnostic information about the array of cells (both real and simulated) and additional damage information. Local agent algorithms have been developed that demonstrate emergent behavior of the complex multi-agent system, through the formation of impact damage boundaries and impact networks. The system has been shown to operate well for multiple impacts. and to demonstrate robust reconfiguration in the presence of damage to numbers of cells
Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 4 - Phase 1 Implementation of the Concept Demonstrator
This report describes the first phase of the implementation of the Concept Demonstrator. The Concept Demonstrator system is a powerful and flexible experimental test-bed platform for developing sensors, communications systems, and multi-agent based algorithms for an intelligent vehicle health monitoring system for deployment in aerospace vehicles. The Concept Demonstrator contains sensors and processing hardware distributed throughout the structure, and uses multi-agent algorithms to characterize impacts and determine an appropriate response to these impacts
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