2,822 research outputs found
The Self-Assembly of Particles with Isotropic Interactions
This is an author-created, un-copyedited version of an article accepted for publication in Journal of Physics: Condensed Matter. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0953-8984/25/32/325101.A generic field-theoretic model for the self-assembly of particles with isotropic interactions,
motivated by ideas in DNA-mediated colloidal assembly, is presented. A simplest possible
system of colloids in explicit solvent is examined to determine the ability of non-connected
particles to form complex nanometre or micron scale equilibrium structures in the absence of
confounding kinetic effects. It is found that non-trivial morphologies are possible and that, for
this effectively one component system, these parallel the phases of diblock copolymer melts
for certain parameter choices, despite the absence of connectivity or packing frustration in the
model. An explanation for the morphological similarity between these architecturally disparate
systems is given. For other parameter choices, it is found that meta-stable and defected phases
become more common, and that similarity with block copolymer morphologies decreases
The Self-Assembly of Particles with Isotropic Interactions
This is an author-created, un-copyedited version of an article accepted for publication in Journal of Physics: Condensed Matter. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0953-8984/25/32/325101.A generic field-theoretic model for the self-assembly of particles with isotropic interactions,
motivated by ideas in DNA-mediated colloidal assembly, is presented. A simplest possible
system of colloids in explicit solvent is examined to determine the ability of non-connected
particles to form complex nanometre or micron scale equilibrium structures in the absence of
confounding kinetic effects. It is found that non-trivial morphologies are possible and that, for
this effectively one component system, these parallel the phases of diblock copolymer melts
for certain parameter choices, despite the absence of connectivity or packing frustration in the
model. An explanation for the morphological similarity between these architecturally disparate
systems is given. For other parameter choices, it is found that meta-stable and defected phases
become more common, and that similarity with block copolymer morphologies decreases
Techno-economic analysis of on-grid biomass renewable energy power station: A case study in Caribbean region of Colombia
In this article a techno-economic study of an Electric-Biomass on-grid power plant is
presented, in order to compare the performance and the operating annual cost under some types
of biogas produced from poultry, bovine and porcine manure, and solid urban organic waste,
using the Homer® software to develop many solutions. Certainly, the best set up had the
maximum combined renewable energy with a minimum electric consumption from the grid. The
scheme was integrated by two 500kW biogas-powered electric generator on grid to supply an
average energy of 1401.6kW, with an annual operating cost of $2.09 million when the energy
supply is electric. Results presented a significant operational cost reduction when the biogas
generator is operating on grid, finding an 8.61% of cost decrease using biogas generated from
poultry, bovine and porcine manure, and a 10.53% of cost decrease using biogas from solid
urban organic waste from centers and grocery market places at Caribbean Region of Colombia
Analysis and optimization for the process of glass tempering using autoclave
A mathematical analysis of the glass tempering process was carried out using an
autoclave, varying the operating parameters of the system. It was found that the process time can
be reduced by up to 3.23% by changing the resistance to 15Ω, but increasing the resistance more
than this value would mean compromising the quality of the final product. Thus, it is advisable
to make variations of the resistance between 10Ω and15Ω, which will allow the optimization of
the process time and pressures without affecting the quality of the resul
Bibliometric study of state observer research applied to internal combustion engine
The present study was conducted to evaluate the worldwide scientific production
related to observers applied to internal combustion engines by taking information from the Web
of Science (WoS) database and taking the papers published between 2001 − 2017. The works
found are mostly research articles with a total of 130 articles equivalent to 97.01%, of the 134
articles studied, and it was also noted that the production of this type of work increased in the
last 3 years, with the maximum value in 2015 being 22 articles, even in those 3 years, the
greatest number of references were also found. The United States is the country with the highest
number of publications with 42 followed by People´s Republic of China, France and UK with
41, 11 and 11 respectively. Although the USA is the country with the highest number of
publications, China has consolidated its position as the country with the highest number of
publications and citations in the last 3 years. However, within the top 10 institutes with the
highest number of publications, 4 of them are from the United States, among which Ohio State
University stands out as the institute with the highest number of publications with 16 (11.9%).
On the other hand, the most commonly used words in the documents were observer (91), control
(47), engine (47), based (42) and estimation (41)
Articulation of environmental management in projects of non-conventional energy sources in the Caribbean Colombian region
This work addresses an inclusion methodology based on criteria for the
implementation of non-conventional energy sources and critical environmental factors for the
licensing of the same, which is applied to the case study installation of wind turbines in seawater
desalination plants in Isla Grande - BolÃvar, this study was carried out taking into account field
visits, and previous studies, where its main researchers and observers coincide with the authors
of this article, the proposal includes aspects that involve the matrix of project stakeholders, work
is completed with the qualitative and quantitative analysis of the factors of greater environmental
impact, within the obtained results it is emphasized that the greatest impact that this project
makes to 170 habitants of Isla Grande Bolivar is the changes of the current and/or potential use
of soil, soil contamination and displacement of birds, In mammal, reptile and amphibian
communities, it is suggested that Environmental Management Plans (PMA) be implemented,
such as programs for conservation management, soil resource management, and vegetation and
wildlife management programs, allowing for effective licensing of the project benefiting equally
the interest group
Quinstant Dark Energy Predictions for Structure Formation
We explore the predictions of a class of dark energy models, quinstant dark
energy, concerning the structure formation in the Universe, both in the linear
and non-linear regimes. Quinstant dark energy is considered to be formed by
quintessence and a negative cosmological constant. We conclude that these
models give good predictions for structure formation in the linear regime, but
fail to do so in the non-linear one, for redshifts larger than one.Comment: 9 pages, 14 figures, "Accepted for publication in Astrophysics &
Space Science
Diversity and distribution of type specimens deposited in the Invertebrate section of the Museum of Zoology QCAZ, Quito, Ecuador
The Invertebrate section of the Museum of Zoology QCAZ at the Pontifical Catholic University of Ecuador in Quito maintains nearly two million curated specimens, and comprises Ecuador's largest collection of native taxa. We review 1902 type specimens from 6 subspecies and 320 species in 121 genera and 42 families, currently kept in the Museum. The list includes 116 holotypes, 10 allotypes, 1774 paratypes and 2 neoparatypes. The collection of type specimens is particularly strong in the Coleoptera (family Carabidae and Staphylinidae) and Hymenoptera. However, other insect orders such as Diptera and Lepidoptera and non-insect arthropods such as Acari, Aranea and Scorpiones, are moderately represented in the collection. This report provides original data from labels of every type specimen record. An analysis of the geographic distribution of type localities showed that collection sites are clustered geographically with most of them found towards the northern region of Ecuador, in Pichincha, Cotopaxi and Napo provinces. Sites are mainly located in highly accessible areas near highways and towns. Localities with a high number of type species include the cloud forest reserve Bosque Integral Otonga and Parque Nacional Yasuni in the Amazon rainforest near PUCE's Yasuni Scientific Station. Type localities are not well represented in the Ecuadorian National System of Protected Areas. Future fieldwork should include localities in the southern region of Ecuador but also target less accessible areas not located near highways or towns. We discuss the value of the collection as a source of information for conservation and biodiversity policies in Ecuador
Review article: the diagnostic approach and current management of chylous ascites
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138889/1/apt14284.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138889/2/apt14284_am.pd
Separating N2O production and consumption in intact agricultural soil cores at different moisture contents and depths
Agricultural soils are a major source of the potent greenhouse gas and ozone depleting substance, N2O. To implement management practices that minimise microbial N2O production and maximise its consumption (i.e. complete denitrification) we must understand the interplay between simultaneously occurring biological and physical processes, especially how this changes with soil depth. Meaningfully disentangling these processes is challenging and typical N2O flux measurement techniques provide little insight into subsurface mechanisms. Additionally, denitrification studies are often conducted on sieved soil in altered O2 environments which relate poorly to in situ field conditions. Here, we use a novel dual headspace system with field-relevant O2 concentrations to incubate intact sandy clay loam textured agricultural topsoil (0-10 cm) and subsoil (50-60 cm) cores for 3-4 d at 50 and 70% water filled pore space (WFPS), respectively. 15N-N2O pool dilution and an SF6 tracer were used to determine the relative diffusivity (Ds/D0) and the net N2O emission and gross N2O emission and consumption rates. The relationship between calculated fluxes from the below- and above- soil core headspaces confirmed that the system performed well. We found no difference in Ds/D0 between soil depth fractions, which was probably because of the preservation of preferential flow pathways in intact cores. Both gross N2O emissions and uptake were not different with depth but were higher in the 50% WFPS, contrary to expectation. We attribute this to aerobic denitrification and simultaneously occurring denitrification and nitrification for the gross consumption and emission of N2O, respectively. Here, we developed a novel system that allows careful control of conditions and, with a headspace below and above a soil core, a more realistic reconstruction of in situ gas dynamics. We provide further evidence of substantial N2O consumption in drier soil and without net negative N2O emissions. The results from this study are important for the future application of the 15N-N2O pool dilution method and N budgeting and modelling, as required for improving management to minimise N2O losses
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