1,375 research outputs found
The Latest Home Education Challenge: The Relationship between Home Schools and Public Schools
Biorefinery concept with green solvents towards the phenolic valorization
The efficient separation, hydrolysis and conversion of principal components of lignocellulosic biomass allows to produce chemicals and value added compounds. Ionic liquids (ILs) have been used for the pre-treatment and fractionation of biomass.1-3 The pre-treatment reveals that phenolic compounds were found in the IL phase. This work was devoted for the extraction of phenolic compounds from the recovered IL
liquid using several adsorption resins in small scale batch processes. Phenolic compounds, such as vanillin, catechol and flavonoids were identified in extraction samples and also quantified. Temperature, residence time and water amount were evaluated in order to find optimal extraction conditions of phenolic compounds from IL
Economic, social and environmental impacts attained by the use of the effluents generated within a small-scale biorefinery concept
ABSTRACT: Biorefineries are emerging as the proper route to defeat climate change and other social, socio-economic and environmental concerns. So far, no residual lignocellulosic biomass-based biorefineries have been yet industrially implemented, mainly due to its economic viability. This article exposes some elements that may help overcome the bottlenecks associated to its social, economic and environmental sustainability: small-scale approaches, biomass valorisation through added-value products and near-zero effluent.info:eu-repo/semantics/publishedVersio
Spatial and Temporal Variation of Coyote (Canis latrans) Diet in Calgary, Alberta
We examined the diet of a portion of Calgary’s urban coyotes to provide baseline data on feeding ecology, to determine spatial and seasonal effects on diet, and to assess whether anthropogenic food sources (primarily garbage) and domestic cats or dogs were part of coyote diet. Bi-weekly surveys of seven study sites were conducted between August 2006 and September 2007. We analyzed 484 coyote scats. The top five prey types consumed by the coyotes studied were small mammals (84.71%), herbaceous plants (44.63%), crabapples (33.88%), woody plants (16.94%) and anthropogenic food sources (14.05%). Domestic animals – cats (Felis catus) and dogs (Canis familiaris) – were found in 6 scats (1.24% of all scats sampled). Large parks had the greatest amount of scats containing native berries (χ26=1700, p\u3c0.001) while smaller parks had higher levels of crabapples (χ26=3700, p\u3c0.001) and anthropogenic content (χ26=413.4, p\u3c0.001) in scats. Scats containing domestic animals were relatively few, highly localized and occurred primarily in the Calgary neighbourhood with the most frequent reports of aggression/predation behaviour in coyotes. Herbaceous plants (χ22=89.273, p\u3c0.001), crabapples (χ22=5023, p\u3c0.001) small mammals (χ22=755.3, p\u3c0.001) and anthropogenic food sources (χ22=183.9, p\u3c0.001) were all consumed most during the Dispersal season. Woody plants (χ22=998.0, p\u3c0.001) were consumed significantly more during Pup-Rearing. Coyotes in Calgary consume predominantly natural prey items. However, the presence of anthropogenic food items in 14% of scats suggests heightened risk of food conditioning, a potential for habituation to humans, which can increase human-coyote conflict. We recommend stricter enforcement of garbage laws, responsible husbandry practices with domestic pets (leash animals), and targeted educational campaigns
Ionic liquids as a tool for lignocellulosic biomass fractionation
Lignocellulosic biomass composes a diversity of feedstock raw materials representing an abundant and renewable carbon source. In majority lignocellulose is constituted by carbohydrate macromolecules, namely cellulose and hemicellulose, and by lignin, a polyphenilpropanoid macromolecule. Between these biomacromolecules, there are several covalent and non-covalent interactions defining an intricate, complex and rigid structure of lignocellulose. The deconstruction of the lignocellulosic biomass makes these fractions susceptible for easier transformation to large number of commodities including energy, chemicals and material within the concept of biorefinery. Generally, the biomass pre-treatment depends on the final goal in the biomass processing. The recalcitrance of lignocellulose materials is the main limitation of its processing once the inherent costs are excessively high for the conventional pre-treatments. Furthermore, none of the currently known processes is highly
selective and efficient for the satisfactory and versatile use, thus, new methodologies are still studied broadly. The ionic liquid technology on biomass processing is relatively recent and first studies were focused on the lignocellulosic biomass dissolution in different ionic liquids (ILs). The dissolution in IL drives to the structural changes in the regenerated biomass by reduction of cellulose crystallinity and lignin content contrasting to the original biomass. These findings provided ILs as tools to perform biomass pre-treatment and the advantageous use of their specific properties over the conventional pre-treatment processes. This review shows the critical outlook on the study of biomass dissolution and changes occurred in the biomass during this process as well as on the influence of several crucial parameters that govern the dissolution and further pre-treatment process. The review of currently known methods of biomass fractionation in IL and aqueous-IL mixtures is also discussed here and perspectives regarding these topics are given as well
A Bayesian Point Process Model for User Return Time Prediction in Recommendation Systems
In order to sustain the user-base for a web service, it is important
to know the return time of a user to the service. We propose a
Bayesian point process, log Gaussian Cox process (LGCP), to model
and predict return time of users. It allows encoding the prior do-
main knowledge and non-parametric estimation of latent intensity
functions capturing user behaviour. We capture the similarities
among the users in their return time by using a multi-task learning
approach. We show the effectiveness of the proposed approaches
on predicting the return time of users to last.fm music service
Green chemistry and the biorefinery concept
Green Chemistry and Biorefinery concepts are two approaches helping to develop new and more sustainable processes. The implementation of both methodologies impels to fossil-independent future with bioeconomy based on natural feedstock like biowaste and industrial by-products. The development of technologies for valorisation of these resources is a key role of society in the creation of sustainable and more environmentally friendly future
An Outlook on the Localisation and Structure-Function Relationships of R Proteins in Solanum
The co-evolution of plants and plant-pathogens shaped a multi-layered defence system in plants, in which Resistance proteins (R proteins) play a significant role. A fundamental understanding of the functioning of these R proteins and their position in the broader defence system of the plant is essential. Sub-project 3 of the BIOEXPLOIT programme studies how R proteins are activated upon effector recognition and how recognition is conveyed in resistance signalling pathways, using the solanaceous R proteins Rx1 (from S. tuberosum spp. andigena; conferring extreme resistance against Potato Virus X), I-2 (from S. lycopersicon; mediating resistance to Fusarium oxysporum) and Mi-1.2 (from S. lycopersicon; conferring resistance to Meloidogyne incognita) as model systems. The results obtained in this project will serve as a model for other R proteins and will be translated to potential applications or alternative strategies for disease resistance. These include the modification of the recognition specificity of R proteins with the aim to obtain broad spectrum resistance to major pathogens in potato
High pressure vapour-liquid equilibrium of volatiles in supercritical carbon dioxide
Binary vapour-liquid equilibrium of thymoquinone and carbon dioxide at the isothermal conditions was carried out at temperature 323.15 K and pressures
from 6 to 10 MPa. The experimental data were fitted to the Soave-Redlich-Kwong equation of state. Results could be used for selection of process parameters in separation of volatiles from raw oil or for evaluation of existing separation technologies
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