76 research outputs found
Projecting Pathways to Food-Energy-Water Systems Sustainability through Ontology
No full textThe FEWsOnt ontology models major structural and dynamic concepts of the food-energy-water (FEW) systems from the complex system perspective by defining the emergent, nonlinear, and scale-invariant state transitions and behaviors of the network elements that result from natural and planned processes. The model represents the semantics of concepts such as security, footprint, challenge, risk, impact, and uncertainty in relation to governance and assessment of the level of sustainability of the FEW systems in varied domains of usage. The ontology will allow stakeholders working with the FEW systems' data to draw new inferences using semantic facts and discover insights and relationships among the systems' elements to make improved assessment and decisions toward sustainable growth. The knowledge-based model will lead users to optimize the tradeoffs and identify and prevent adverse changes to the FEW systems in relation to the interacting natural and social systems. The annotated terminology and formalized interactions in the ontology will facilitate the integration of the diverse FEW data types, improve communication among researchers, and help to reduce environmental stresses
Probing the Upper Band Gap of Atomic Rhenium Disulfide Layers
No full textHere, we investigate the ultrafast carrier dynamics and electronic states of exfoliated ReS2 films using time-resolved second harmonic generation (TSHG) microscopy and density functional theory (DFT) calculations. The second harmonic generation (SHG) of layers with various thicknesses is probed using a 1.19-eV beam. Up to ~13 nm, a gradual increment is observed, followed by a decrease caused by bulk interferometric light absorption. The addition of a pump pulse tuned to the exciton band gap (1.57 eV) creates a decay-to-rise TSHG profile as a function of the probe delay. The power and thickness dependencies indicate that the electron–hole recombination is mediated by defects and surfaces. The two photon absorptions of 2.38 eV in the excited state that are induced by pumping from 1.57 to 1.72 eV are restricted because these transitions highly correlate with the forbidden d–d intrasubshell orbital transitions. However, the combined usage of a frequency-doubled pump (2.38 eV) with wavelength-variant SHG probes (2.60–2.82 eV) allows us to vividly monitor the variations in TSHG profiles from decay-to-rise to rise-to-decay, which imply the existence of an additional electron absorption state (s-orbital) at an approximate distance of 5.05 eV from the highest occupied molecular orbital states. This observation was critically examined by considering the allowance of each electronic transition and a small upper band gap (~0.5 eV) using modified DFT calculations. © 2018, The Author(s).1
Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems
No full textSeawater desalination is a rapidly growing coastal industry that is increasingly threatened by algal blooms. Depending on the severity of algal blooms, desalination systems may be forced to shut down because of clogging and/or poor feed water quality. To maintain stable operation and provide good feed water quality to seawater reverse osmosis (SWRO) systems, ultrafiltration (UF) pre-treatment is proposed. This research focused on assessing the ability of UF and other pre-treatment technologies to reduce biofouling in SWRO systems. An improved method to measure bacterial regrowth potential (BRP) was developed and applied at laboratory, pilot and full scale to assess the ability of conventional UF (150 kDa) and tight UF (10 kDa) alone and in combination with a phosphate adsorbent to reduce regrowth potential and delay the onset of biofouling in SWRO. The improved bacterial regrowth potential method employs a natural consortium ofmarine bacteria as inoculum and flow cytometry. The limit of detection of the BRP method was lowered to 43,000 ± 12,000 cells/mL,which is equivalent to 9.3 ± 2.6 μg-Cglucose/L. The reduction in bacterial regrowth potential after tight UF (10 kDa) was 3 to 4 times higher than with conventional UF (150 kDa). It was further reduced after the application of a phosphate adsorbent, independent of pore size of the UF membrane. Pilot studies demonstrated that the application of tight UF (10 kDa) coupled with a phosphate adsorbent consistently lowered the bacterial regrowth potential and no feed channel pressure drop increase was observed in membrane fouling simulators (MFS) over a period of 21 days. The study also showed that nonbackwashable fouling of UF membranes varied strongly with the type of algal species and the algal organic matter (AOM) they release. The presence of polysaccharide (stretching - OH) and sugar ester groups (stretching S=O) was the main cause of nonbackwashable fouling. In conclusion, this study showed that an improved BRP method is suitable for the assessment of SWRO pre-treatment systems and it can be a useful tool to develop potential strategies to mitigate biofouling and improve the sustainability of SWRO systems
Planetary stewardship in an urbanizing world: beyond city limits
No full textCities are rapidly increasing in importance as a major factor shaping the Earth system, and as such must take corresponding responsibility. With currently over half of the world population, cities are supported by resources originating from primarily rural regions that are often located around the world far distant from the urban loci of use. The multiple and complex environmental and social challenges the world faces require interconnected solutions and a coordinated governance approach to planetary stewardship. There is a new opportunity to conceptualize a key component of planetary stewardship as a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could not only increase their capacity to effect change and foster stewardship at the planetary scale but also increase their resource security
Emerging low-carbon urban mega-projects
No full textThis is the author accepted manuscript. The final version is available from Springer via the DOI in this recordThis chapter focuses on the recent trend in some geographical locations (particularly China and the United Arab Emirates) towards building large-scale low-carbon city projects. These low-carbon cities are increasingly being described as mega-projects due to their scale and involvement of large-scale experimental approaches to ways of organizing the low-carbon city. The chapter discusses some of the main trends towards the development of low-carbon eco-city projects since 2000, and then introduces the two main low-carbon city mega-projects currently being developed
Engineering the Microbial Platform for the Production of Biologics and Small-Molecule Medicines
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Engineering the Microbial Platform for the Production of Biologics and Small-Molecule Medicines
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
A Resilience Assessment Framework of Infrastructure Systems by Integrating Social Equity to Support Disaster Resilience Decision Making
No full textResilient infrastructure, which better withstands, adapts, and quickly recovers from disasters, can limit disaster impacts, such as disruptions to infrastructure services and time and efforts needed for recovery. However, in the context of a disaster, the impacts or disruptions on the infrastructure are not evenly distributed across different communities. Thus, we need to account for such disparities (or inequalities) when assessing infrastructure resilience.
To address this need, this dissertation presents a new social-welfare-based infrastructure resilience assessment (SW-Infra-RA) model for quantifying the collective resilience of infrastructure serving multiple communities. This model accounts for (1) disaster inequality – the unequal distribution of disaster impacts on infrastructure across different communities, and (2) disaster vulnerability – the disaster impacts on infrastructure of the communities that suffer from the most severe impacts, both of which have impacts on the collective resilience of infrastructure. The proposed model is theoretically grounded on the social welfare theory and social welfare functions. It also leverages studies related to Social Vulnerability Index and the Resilient Triangle framework. The dissertation presents the conceptual notions and mathematical functions of the SW-Infra-RA model. A set of hypothetical and real case studies were conducted to illustrate the use of the proposed model to assess infrastructure resilience.
The results generated using this model could be utilized by decision makers to better understand the uneven distribution of disaster impacts across communities and identify communities that are severely impacted from a disaster. Such information about inequalities and vulnerabilities of the impacted region could help decision makers prioritize disaster assistance, resources for recovery, and future infrastructure investment toward the vulnerable communities. Overall, the study has the potential to facilitate equitable resilience planning by allowing both decision makers and community personnel to better understand the links between resilience planning and equity in their communities
Bovine parainfluenza-3 antibodies in veal calves supplemented with cinnamaldehyde or lactoferrin
No full textObjective
Our objective was to investigate the effects of 2 immune modulatory compounds, cinnamaldehyde and lactoferrin, on potentiating the immune response to bovine parainfluenza-3 virus (bPI3) vaccination.
Materials
On arrival to the growing facility, veal calves were randomized to 1 of 3 treatments: control (no supplement), lactoferrin (1 g/d in milk replacer for 7 d), or cinnamaldehyde (1 g/d in milk replacer for 21 d). Plasma anti-bPI3 IgG response was assayed by indirect ELISA before (d 0) and 28 d after vaccination. Antibody titers were represented as sample-to-positive ratio, and a mixed linear regression analysis was used to compare titers between treatments, cohorts, and d 0 versus d 28.
Results and Discussion
Stress and crowding during transit leaves veal calves susceptible to respiratory viral pathogens. Bovine parainfluenza-3 virus is a principle etiological agent of bovine respiratory disease complex. Prophylactic antibiotic administration is a common practice to prevent diseases; however, this can lead to antibiotic resistance. Therefore, research on antimicrobial alternatives is warranted. Antibody titers against bPI3 were different between d 0 and 28 (P < 0.0001), but no effect was observed between treatments (P = 0.21) or treatment by day (P = 0.74); however, antibody titers were different from d 0 and 28 between cohorts (P = 0.01).
Implications and Applications
Antibodies detected are suspected to be of maternal origin. Further research is necessary to determine an optimal vaccination schedule to overcome maternal immunity and to estimate mucosal IgA antibodies. In addition, an appropriate dose, duration, and route of administration of cinnamaldehyde and lactoferrin must be considered
Formation of nanosized monolayer MoS2 by oxygen-assisted thinning of multilayer MoS2
No full textWe report the controllable nanosized local thinning of multi-layer (2 L and 3 L)-thickness MoS2 films down to the monolayer (1 L) thickness using the simple method of annealing in a dry oxygen atmosphere. The annealing temperature was optimized in the range of 240 °C to 270 °C for 1.5 h, and 1 L thick nanosized pits were developed on the uniform film of the 2 L and 3 L MoS2 grown using the chemical vapor deposition method. We characterized the formation of the 1 L nanosized pits using nanoscale confocal photoluminescence (PL) and Raman spectroscopy. We observed that the PL intensity increased and the Raman frequency shifted, representative of the characteristics of 1 L MoS2 films. A subsequent hydrogen treatment process was useful for removing the oxygen-induced doping effect resulting from the annealing. © 2016 Author(s)6711sciescopu
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