3,337 research outputs found
The Local Compressibility of Liquids near Non-Adsorbing Substrates: A Useful Measure of Solvophobicity and Hydrophobicity?
We investigate the suitability of the local compressibility chi(z) as a
measure of the solvophobicity or hydrophobicity of a substrate. Defining the
local compressibility as the derivative of the local one-body density w.r.t.
the chemical potential at fixed temperature, we use density functional theory
(DFT) to calculate chi(z) for a model fluid, close to bulk liquid-gas
coexistence, at various planar substrates. These range from a `neutral'
substrate with a contact angle of approximately 90 degrees, which favours
neither the liquid nor the gas phase, to a very solvophobic, purely repulsive
substrate which exhibits complete drying (i.e. contact angle 180 degrees). We
find that the maximum in the local compressibility, which occurs within one-two
molecular diameters of the substrate, and the integrated quantity chi_ex (the
surface excess compressibility, defined below) both increase rapidly as the
contact angle increases and the substrate becomes more solvophobic. The local
compressibility provides a more pronounced indicator of solvophobicity than the
density depletion in the vicinity of the surface which increases only weakly
with increasing contact angle. When the fluid is confined in a parallel slit
with two identical solvophobic walls, or with competing solvophobic and
solvophilic walls, chi(z) close to the solvophobic wall is altered little from
that at the single substrate. We connect our results with simulation studies of
water near to hydrophobic surfaces exploring the relationship between chi(z)
and fluctuations in the local density and between chi_ex and the mean-square
fluctuation in the number of adsorbed molecules.Comment: 23 pages, 9 figures, submitted to Journal of Physics: Condensed
Matter as a Special Issue Articl
Interaction matters: Strategies to promote engaged learning in an online introductory nutrition course
Fostering interaction in the online classroom is an important consideration in ensuring
that students actively create their own knowledge and reach a high level of achievement
in science courses. This study focuses on fostering interaction in an online introductory
nutrition course offered in a public institution of higher education in Hawai‘i, USA.
Interactive features included synchronous discussions and polls in scheduled sessions,
and social media tools for sharing of information and resources. Qualitative student
feedback was solicited regarding the new course features. Findings indicated that
students who attended monthly synchronous sessions valued live interaction with peers
and the instructor. Issues identified included technical difficulties during synchronous
sessions, lack of participation on the part of fellow students in discussion and inability to
attend synchronous sessions due to scheduling conflicts. In addition, few students made
use of the opportunity to interact via social media. While students indicated that the
interactive components of the course were valuable, several areas in which improvement
may be made remain. Future studies may explore potential solutions to issues identified
with new features to further promote interaction and foster learning in the course.
Recommendations for instructors who are interested in offering online science courses in
higher education are provided
N-methyl-N-alkylpyrrolidinium nonafluoro-1-butanesulfonate salts : Ionic liquid properties and plastic crystal behaviour
A series of N-methyl-N-alkylpyrrolidinium nonafluoro-1-butanesulfonate salts were synthesised and characterised. The thermophysical characteristics of this family of salts have been investigated with respect to potential use as ionic liquids and solid electrolytes. N-Methyl-N-butylpyrrolidinium nonafluoro-1-butanesulfonate (p1,4NfO) has the lowest melting point of the family, at 94 °C. Electrochemical analysis of p1,4 NfO in the liquid state shows an electrochemical window of ~6 V. All compounds exhibit one or more solid–solid transitions at sub-ambient temperatures, indicating the existence of plastic crystal phases.<br /
GIS-based methodology for prioritization of preparedness interventions on road transport under wildfire events
Climate change is leading to a rise in the occurrence and intensity of wildfires, exacerbated by the growing encroachment of communities into the natural environment, posing challenges to our global capacity to respond to wildfires. During wildfire events, road transport infrastructure becomes crucial for the evacuation of people and accessibility to an emergency by first responders. Nevertheless, resilience management of transportation infrastructure affected by wildfires is poorly considered, despite its relevant role and high exposure to wildfires. Therefore, this study proposes a new methodology to estimate the priority level for wildfire preparation by combining exposure and criticality of road transportation infrastructure to wildfire hazards with consideration of different wildfire categories. The analysis is conducted at the system level considering interdependencies and redundancies among infrastructure components and using a geographic information system (GIS) to automate the modelling process and visualization of results. The proposed methodology is applied to a case study in the Leiria region of Portugal, demonstrating its utility in prioritizing economic resources and decision-making for areas requiring preparation. This approach can serve as a resilience-based tool for decision-making, supporting the implementation of effective adaptation strategies to enhance wildfire resilience.This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020. This work is financed by national funds through the Foundation for Science and Technology (Fundaç˜ao para a ciˆencia e tecnologia, FCT, Portugal), under grant agreement 2020.05755.BD attributed to the first author
Enhancing infrastructure resilience in wildfire management to face extreme events: Insights from the Iberian Peninsula
Factors such as human activity and climate change are contributing to an increase in the frequency and intensity of wildfires. This problem has challenged society’s knowledge, response capacity, and resilience, revealing its inadequacy to cope with the new wildfire regime characterized by extreme wildfire events (EWE). Policies on wildfire management mainly focus on suppression and managing emergencies, which may be insufficient to reduce EWE’s incidence and cope with its impact. Consequently, there is a lack of tools to support decision-making in wildfire management in other important aspects, such as prevention and protection. This study examines global wildfire policies specifically in the Iberian Peninsula (Portugal and Spain), including cross-border policies. A GIS-based tool to evaluate different normal and extreme wildfire management policies is applied to a cross-border case study, paying attention to the impact on critical land-based transport systems. A relevant outcome of the tool application is that suppression must be complemented with other wildfire management strategies in the analyzed area. The gained insights can help stakeholders to improve decision-making in wildfire management to successfully address EWE.This work was partly financed by FCT/ MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/ 04029/2020 (doi.org/10.54499/UIDB/04029/2020), and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020
The Impact of the Extent of Lymphadenectomy on Oncologic Outcomes in Patients Undergoing Radical Cystectomy for Bladder Cancer : A Systematic Review
Copyright © 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.Peer reviewedPostprin
Critical drying of liquids
We report a detailed simulation and classical density functional theory study
of the drying transition in a realistic model fluid at a smooth substrate. This
transition (in which the contact angle ) is shown to be
critical for both short ranged and long-ranged substrate-fluid interaction
potentials. In the latter case critical drying occurs at exactly zero
attractive substrate strength. This observation permits the accurate
elucidation of the character of the transition via a finite-size scaling
analysis of the density probability function. We find that the critical
exponent that controls the parallel correlation length, i.e.
the extent of vapor bubbles at the wall, is over twice as large as predicted by
mean field and renormalization group calculations. We suggest a reason for the
discrepancy. Our findings shed new light on fluctuation phenomena in fluids
near hydrophobic and solvophobic interfaces.Comment: 5 pages plus supplementary information. To appear in Physical Review
Letter
Identifying Epidermolysis Bullosa Patient Needs and Perceived Treatment Benefits:An Explorative Study Using the Patient Benefit Index
Epidermolysis bullosa (EB) is a genetic blistering skin condition for which no cure exists. Symptom alleviation and quality of life are therefore central to EB care. This study aimed to gain insight into EB patient needs and benefits from current clinical care. Two questionnaires were administered cross-sectionally to adult EB patients at the Dutch expertise centre for blistering diseases. Patient needs and benefits were analyzed using the patient benefit index survey (PBI-S). Ancillary data were compiled pertaining to self-reported EB severity, pain and pruritus, as well as current and previous treatments. In total, 104 participants were included (response rate 69.8%). Sixty-eight participants comprised the analyzed cohort (n = 36 omitted from analysis). The needs given the highest importance were to get better skin quickly (64.7%) and to be healed of all skin alterations (61.8%). A positive correlation between pain and EB severity and the importance of most needs was observed. Minimal clinically important differences within the PBI-S, relating to reported benefits from clinical care, were reported by 60.3% of the cohort. This study highlights a discrepancy between patient needs and feasible treatment outcomes. Utilizing the PBI-S in conjunction with well-established multidisciplinary care may catalyze the process of tailoring treatments to the needs of individual patients
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