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Supercritical water gasification of biomass model compounds: A review
No full textIn recent decades, conversion of bio-renewable resources to biofuels or bio-based chemicals has received a great deal of attention, owing to the resource exhaustion, environmental concerns, and socio-economic issues of fossil fuels. One of the promising biomass conversion routes is the supercritical water gasification (SCWG) of biomass for producing H2 or combustible gases. SCWG is an effective conversion technology, particularly for high water-containing feedstocks, because of its unique advantage by avoiding the costly feedstock de-watering/drying process. To improve gasification performance, it is necessary to have a deeper understanding of the basic chemistry and kinetics of biomass SCWG. Therefore, this review focuses on the performance (chemistry and kinetics) of SCWG of biomass model compounds (cellulose, hemicellulose, lignin, lipid, and protein), and more importantly the binary or multi-component systems to elucidate the interaction effects induced by two or more biomass components in supercritical water (SCW). In addition, the advantages and technical challenges for using SCW as the reaction medium are discussed. Finally, the future R&D directions are presented.MitacsGreenfield Global IncNSERC-Discovery GrantCanadian Forest Innovation and Energy Innovation Programs of Natural Resources Canad
Supercritical water gasification of biocrude oil from low-temperature liquefaction of algal lipid extraction residue
No full textThe lipid extraction followed by transesterification is the conventional approach for producing liquid bio-fuels from algae, during which protein and carbohydrates in algae are treated as a waste. In this study, the remaining solid after lipid extraction from algae was applied as the feedstock to produce biocrude oil by low-temperature liquefaction. Catalytic liquefaction of lipid extraction by-product was performed at 200–250 °C for 60 min, and compared to commonly used feedstocks (i.e., agricultural and forestry residues). The biocrude oil yield from lipid by-product was 65.4–78.5 wt% and higher than that from rubberwood sawdust (48.8–59.9 wt%) or bamboo sawdust (47.9–63.7 wt%). Besides, the biocrude oil from lipid extraction by-product mainly consisted of nitrogenated compounds, hydrocarbons, aromatics, ketones, and alcohols. Following this, this biocrude oil obtained from liquefaction of algal lipid extraction by-product at the optimal conditions was employed as the feedstock to generate combustible gases by catalytical supercritical water gasification (SCWG) at 500 °C for 60 min with a feedstock loading of 10 wt%. The results indicated that the highest gas yield was obtained when using K2CO3 as the catalyst. Overall, this study provides a possible route to improve the economy of algae-based biorefinery by valorizing the lipid extraction residue to generate biocrude oil and subsequently converts into combustible gases via SCWG.MitacsGreenfield Global IncNSERC-Discovery GrantCanadian Forest Innovation and Energy Innovation Program
Development of a disposable single-nozzle printhead for 3D bioprinting of continuous multi-material constructs
No full textFabricating multi-cell constructs in complex geometries is essential in the field of tissue engineering, and three-dimensional (3D) bioprinting is widely used for this purpose. To enhance the biological and mechanical integrity of the printed constructs, continuous single-nozzle printing is required. In this paper, a novel single-nozzle printhead for 3D bioprinting of multi-material constructs was developed and characterized. The single-nozzle multi-material bioprinting was achieved via a disposable, inexpensive, multi-fuse IV extension set; the printhead can print up to four different biomaterials. The transition distance of the developed printhead was characterized over a range of pressures and needle inner diameters. Finally, the transition distance was decreased by applying a silicon coating to the inner channels of the printheadCanada Foundation for InnovationNatural Sciences and Engineering Research Council of Canad
Calving location preference and changes in lying and exploratory behavior of preparturient dairy cattle with access to pasture
No full textThe objectives of this study were to (1) describe the calving location of dairy cattle given access to a pasture and barn; (2) identify factors associated with calving location; and (3) compare the lying and exploratory behavior of cows in the 24 h before calving and a previous day. Seventy-two Holstein dairy heifers and cows (n = 36 nulliparous and n = 36 primiparous and multiparous combined) were housed in a covered bedded-pack barn (167.4 m2) with free access to 2.1 ha of pasture. The composition of the group was dynamic, because cows were moved in weekly at 19 ± 6 d [mean ± standard deviation (SD)] before their calving date, and were removed immediately after calving. To facilitate data collection, we divided the environment into 9 sections, including the barn (section 1; 167.4 m2), 7 sections of open pasture (sections 2 to 8; 2,402 ± 60 m2), and 1 section of pasture surrounded by natural forage cover (section 9; 3,593 m2). We then collapsed these 9 sections into 3 distinct areas for further analysis: the barn, open pasture, and natural forage cover. Animals were fitted with accelerometers to measure lying time, lying bout duration, lying bouts, and steps for the 24 h before calving (calving day) and a similar 24 h period 4 to 11 d (median = 7) before calving (baseline day). We included parity (nulliparous vs. primiparous and multiparous) and heat stress [no heat stress = temperature-humidity index (THI) ≤68 vs. heat stress = THI >68 and ≤79] in all analyses; we included time of day and group composition as additional factors that may have affected calving location. We determined exploratory behavior using 10 min instantaneous scan sampling collected from video. At each scan, we recorded the section (1 to 9) the cow or heifer was located in, and then calculated the minimum number of sections that could be crossed between successive scans. Of the total sample, 39% calved in the barn, 26% calved in the open pasture, and 35% calved in the area with natural forage cover. Nulliparous heifers and those calving when heat stress was low (THI ≤68) selected the area with natural forage cover more frequently than the barn. On the calving day, cows spent more time lying down with more short bouts of lying, and crossed more sections compared with the baseline day. Steps were affected by an interactive effect of day, parity, and heat stress; nulliparous heifers took more steps on the calving day during conditions of heat stress compared with no heat stress. Results indicate that cows and heifers had different preferences for their environment at calving, and when provided access to pasture, both changed their lying and exploratory behavior on the day of calving compared with a previous day
Analysis of structural proteins of Atlantic Salmon Bafinivirus - a coronavirus of fish
No full textAtlantic Salmon Bafinivirus (ASBV) is a recently discovered coronavirus of fish, isolated from farmed Atlantic salmon. The ASBV genome, similarly to other bafiniviruses, has 4 major open reading frames (ORFs): replicase polyprotein (pp1a/1b), spike (S), membrane (M), and nucleocapsid (N) proteins. Genome sequence analysis of ASBV revealed a putative sixth protein, a 110 amino-acid polypeptide, which most likely
corresponds to the envelope (E) protein in coronaviruses of the subfamily Coronavirinae.
The main objective of this research was to investigate viral replication and viral genome composition of ASBV. The aims of this research were to characterize the replication kinetics of ASBV, to investigate ASBV receptor binding by partially characterizing the S1 subunit of the S protein, and to investigate transcription studies of a
putative Envelope “E” gene of ASBV. This research was undertaken to advance our understanding of molecular interactions between ASBV and host cells.
Viral replication of ASBV was monitored in KF1 and CHSE-214 fish cell lines using detection of cytopathogenic effects (CPE) and indirect immunofluorescence. CPE was noted in infected KF1 cells, however, was not noted in CHSE-214 cells. Immunofluorescence experiments showed strong fluorescence in the cytoplasm of KF1 cells and weaker fluorescence in CHSE-214 cells, suggesting that the virus is able to affect both KF1 and CHSE-214 cells.
Partial characterization of the S1 subunit of the S protein of ASBV was attempted to determine the location of the receptor binding domain within the S1 subunit of ASBV. Due to the inability to produce concentrated pure proteins from ASBV S protein gene constructs for use in binding assays, this objective was not achieved.
Transcription studies of the ASBV putative “E” gene resulted in preliminary data which may support the existence of an ASBV “E” gene, however at this time it isn’t possible to conclude whether the putative ASBV “E” gene is in fact an envelope protein or homologue. At this time, more in depth research on this topic is suggested in order to further elucidate the role of the putative ASBV “E” gene.
As ASBV is a recently isolated virus, there are a number of specific research questions that currently remain unanswered. An overarching conclusion to this research is the difficulty of characterization of novel fish viruses, and the need for additional research
Biodegradation of bioplastic using anaerobic digestion at retention time as per industrial biogas plant and international norms
No full textBioplastics are gaining interest as an alternative to fossil-based plastics. In addition, biodegradable bioplastics may yield biogas after their use, giving an additional benefit. However, the biodegradability time in international norms (35 days) far exceeds processing times in anaerobic digestion facilities (21 days). As the bioplastic packaging does not indicate the actual biodegradability, it is important to understand the time required to biodegrade bioplastic if it ends up in the anaerobic digestion facility along with other organic waste. For this work, cellulose bioplastic film and polylactic acid (PLA) coffee capsules were digested anaerobically at 55 ℃ for 21 days and 35 days, which are the retention times for industrial digestors and as set by international norms, respectively. Different sizes of bioplastics were examined for this work. Bioplastic film produced more biogas than bioplastic coffee capsules. The biodegradability of bioplastic was calculated based on theoretical biogas production. With an increase in retention time, biogas production, as well as biodegradability of bioplastic, increased. The biodegradability was less than 50% at the end of 35 days for both bioplastics, suggesting that complete degradation was not achieved, and thus, the bioplastic would not be suitable for use in biogas digesters currently in use.MitacsUniversity of Prince Edward Islan
First example of cationic cyclopentadienyliron based chromene complexes and polymers: Synthesis, characterization, and biological applications
No full textThe present work encompasses development of a new class of active antimicrobial agents of the ɳ6-arene-ɳ5-cyclopentadienyliron (II) complexes and polymers to expand the existing family of antimicrobials. The design of the first example of these cationic organoiron complexes, incorporating chromene moieties, was successfully accomplished in good yield via the Steglich esterification, followed by the nucleophilic aromatic substitution reactions to isolate their polymeric analogues. Meanwhile, the structural identities of the new materials were confirmed using 1H and 13C NMR, IR, and elemental analysis. The molecular weight of the new polymeric materials was estimated using viscosity measurements, and was found to be in the range of 10,000 and 31,000. The chromene-containing organoiron complexes displayed reversible reduction behaviors as their functionalized polymers. Meanwhile, the TGA thermogram revealed initial weight losses due to the cleavage of the cationic iron moieties, while the second weight losses were dependent upon the etheric linkages in the polymer backbones. This study, therefore, focuses on the exploration of the antimicrobial and antitumor performance of the new materials along with their structure activity relationship
Exfoliated MoS2–polyaniline nanocomposites: Synthesis and characterization
No full textKeywords: Polyaniline; Molybdenum disulfide; Nanocomposite electronic conductivity Abstract Exfoliated MoS.sub.2--PANI nanocomposites with varying percentage by weight of exfoliated 2H--MoS.sub.2 were synthesized and characterized by several techniques. The characterization techniques used were powder X-ray diffraction, electrical conductivity, Seebeck coefficient measurements, thermogravimetric analysis, and transmission electron microscopy. An intriguing observation was observed in the conductivity data as several of the nanocomposites that contained 5 to 15% by weight of exfoliated MoS.sub.2 yielded higher conductivity than a sample of pure PANI synthesized under the same conditions. Exfoliated 2H--MoS.sub.2 has very low conductivity due to the disorder of the system, so this increase was not expected. This may indicate that the presence of MoS.sub.2 may improve the conductivity of PANI by altering its doping, or by enhancing PANI ordering or, that PANI may be stabilizing MoS.sub.2 in its 1T zero band gap metallic form, which is higher in conductivit
Generational Bridges: Supporting Literacy Development With Elder Storytelling and Video Performance
No full textThis paper describes our implementation of digital storytelling within a First Nations
community
elementary school in eastern Canada. Our aim with this project was to support community engagement
in the school, while promoting literacy development, by inviting Elders to share their stories, both
traditional and modern lived experiences, with
children in a grade 4/5 split class. Positioned as a
participatory action research project, anchored in Indigenous methodologies, the project was developed
through meetings with community members to build on the strengths of the community. Reflections fro
m
students illustrate that working with Elders gave deeper meaning to the stories they heard and performed
,
and fostered greater engagement in literacy development
Assessing reproductive effects on fish populations: An evaluation of methods to predict the reproductive strategy of fishes
No full textMany environmental monitoring programs include an assessment of the health of fish populations using a sentinel species and include an indicator of reproductive potential. Knowledge of the reproductive strategy of the fish species is critical for data interpretation but is not always known. The reproductive strategy of a species can be determined from detailed histological analyses of ovaries throughout the reproductive cycle however, these studies can be costly and can delay the implementation of a monitoring program. Three quick and cost-effective methods of predicting the reproductive strategy (annual single spawning or annual multiple spawning) are evaluated in this study using predicted probabilities from binary logistic regression models as a means of classifying the reproductive strategies of 18 different fish species in Atlantic Canada. The first method was based on the hypothesis that the variability in the ovary weight-body weight relationship in prespawning females is higher in multiple spawners. This method did not have a good classification rate due to some multiple spawners having low variability. The other two methods involved predictor variables representing the proportion of oocytes in different stages of development and predictor variables representing the distribution of oocyte sizes during the prespawning season for 111 fish (25 different samples for species). Predicted probabilities from these regression models could be used to correctly classify the reproductive strategies of all 25 samples (development stage model) and all but one sample (oocyte size distribution model). These models can be used to estimate the reproductive strategy of a species from a single sample of fish collected during the prespawning period to support species selection and data interpretation in environmental monitoring program