117 research outputs found

    Pertanika Journal of Science & Technology

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    Pertanika Journal of Science & Technology

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    Soft sensor development and process control of anaerobic digestion

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    This thesis focuses on soft sensor development based on fuzzy logic used for real time online monitoring of anaerobic digestion to improve methane output and for robust fermentation. Important process parameter indicators such as pH, biogas production, daily difference in pH and daily difference in biogas production were used to infer alkalinity, a reliable indicator of process stability. Additionally, a fuzzy logic and a rule-based controller were developed and tested with single stage anaerobic digesters operating with cow slurry and cellulose. Alkalinity predictions from the fuzzy logic algorithm were used by both controllers to regulate the organic loading rate that aimed to optimise the biogas process. The predictive performance of a software sensor determining alkalinity that was designed using fuzzy logic and subtractive clustering and was validated against multiple linear regression models that were developed (Partner N° 2, Rothamsted Research 2010) for the same purpose. More accurate alkalinity predictions were achieved by utilizing a fuzzy software sensor designed with less amount of data compared to a multiple linear regression model whose design was based on a larger database. Those models were utilised to control the organic loading rate of a twostage, semi-continuously fed stirred reactor system. Three 5l reactors without support media and three 5l reactors with different support media (burst cell reticulated polyurethane foam coarse, burst cell reticulated polyurethane foam medium and sponge) were operated with cow slurry for a period of seven weeks and twenty weeks respectively. Reactors with support media were proven to be more stable than the reactors without support media but did not exhibit higher gas productivity. Biomass support media were found to influence digester recovery positively by reducing the recovery period. Optimum process parameter ranges were identified for reactors with and without support media. Increased biogas production was found to occur when the loading rates were 3-3.5g VS/l/d and 4-5g VS/l/d respectively. Optimum pH ranges were identified between 7.1-7.3 and 6.9-7.2 for reactors with and without support media respectively, whereas all reactors became unstable at ph<6.9. Alkalinity levels for system stability appeared to be above 3500 mg/l of HCO3 - for reactors without media and 3480 mg/l of HCO3 - for reactors with support media. Biogas production was maximized when alkalinity was 3 between 3500-4500 mg/l of HCO3 - for reactors without support media and 3480- 4300 mg/l of HCO3 - for reactors with support media. Two fuzzy logic models predicting alkalinity based on the operation of the three 5l reactors with support media were developed (FIS I, FIS II). The FIS II design was based on a larger database than FIS I. FIS II performance when applied to the reactor where sponge was used as the support media was characterized by quite good MAE and bias values of 466.53 mg/l of HCO3- and an acceptable value for R2= 0.498. The NMSE was close to 0 with a value of 0.03 and a slightly higher FB= 0.154 than desired. The fuzzy system robustness was tested by adding NaHCO3 to the reactor with the burst cell reticulated polyurethane foam medium and by diluting the reactor where sponge was used as the support media with water. FIS I and FIS II were able to follow the system output closely in the first case, but not in the second. FIS II functionality as an alkalinity predictor was tested through the application on a 28l cylindrical reactor with sponge as the biomass support media treating cow manure. If data that was recorded when severe temperature fluctuations occurred (that highly impact digester performance), are excluded, FIS II performance can be characterized as good by having R2= 0.54 and MAE=Bias= 587 mg/l of HCO3-. Predicted alkalinity values followed observed alkalinity values closely during the days that followed NaHCO3 addition and water dilution. In a second experiment a rulebased and a Mamdani fuzzy logic controller were developed to regulate the organic loading rate based on alkalinity predictions from FIS II. They were tested through the operation of five 6.5l reactors with biomass support media treating cellulose. The performance indices of MAE=763.57 mg/l of HCO3-, Bias= 398.39 mg/l of HCO3-, R2= 0.38 and IA= 0.73 indicate a pretty good correlation between predicted and observed values. However, although both controllers managed to keep alkalinity within the desired levels suggested for stability (>3480 mg/l of HCO3-), the reactors did not reach a stable state suggesting that different loading rates should be applied for biogas systems treating cellulose.New Generation Biogas (NGB

    Biosystems and Food Engineering Research Review 28

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    The Twenty Eighth Annual Research Review describes the ongoing research programme in the School of Biosystems and Food Engineering at University College Dublin over the academic year 2022/23, from the collective research body within the school comprising our academic staff, technical staff, research staff and our early-stage researchers. The research programme covers two main focal areas: Food and Process Engineering as well as Energy and the Environment. Each of these areas is divided into sub-themes as indicated in the Table of Contents, which also includes the name of the research scholar (in bold); the title of the research and the nature of the research programme. The review also highlights the award winners for presentational excellence at the 28th Annual Biosystems and Food Engineering Research Seminar, which was held online in virtual format on Thursday 16th March 2023. The awardees for 2023 are listed in the Appendix A

    The Black Soldier Fly, Hermetia illucens Linnaeus (Diptera: Stratiomyidae): A Novel Approach to Combat Food Waste in Windsor-Essex.

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    Within Ontario alone, approximately 3.7 million tonnes of organic food waste is generated yearly. This waste includes food scraps, wasted food, and plant wastes such as leaves, plant stems, and fruit. Most of it is transported to landfills for composting each year, but the use of landfills as a method of waste management is not sustainable. It adds strain to the environment by releasing harmful greenhouse gases and by demanding landfill space. The current protocols set by the Ontario government, while promising, do not address methods that support the safe disposal of organic waste and conversion into valuable end products that could contribute economic benefits, the black soldier fly presents an opportunity to address this lack. The black soldier fly, Hermetia illucens Linnaeus (Diptera: Stratiomyidae) has the potential to reduce organic waste, including kitchen waste and manure. My dissertation investigated the black soldier fly as a means of waste management within Windsor-Essex, and its role in converting food waste into economically valuable end products. I investigated the black soldier fly’s ability to consume local municipal food waste from within this region. The flies reduced approximately 70% of the waste, and allowed me to develop a baseline for black soldier fly waste reduction within the area. As I measured slower development to adult and reduced waste reduction efficiency compared to a control diet of poultry feed, I investigated the potential role of pre-digestion and fermentation with beneficial microbes in the black soldier fly waste reduction process with the goal of improving the baseline waste reduction efficiency. Fermentation time impacted development and waste reduction efficiency of the black soldier fly. Diets fermented for 0 days had a positive influence on the survival and bioconversion efficiency of the black soldier fly, while diets fermented for 2 days had a positive influence on the relative growth rate and waste reduction efficiency. Diets fermented for longer than 2 days negatively affected the black soldier fly development, growth and waste conversion efficiency. The results show that using beneficial microbes is not straightforward and might depend on the purpose of the bioconversion process. Since larval density influences the waste conversion efficiency, it is essential to rapidly quantify egg numbers for introduction to waste streams. Thus, I developed a commercially-scalable model to quantify the number of eggs oviposited by female black soldier flies based on egg mass weight or volume. The model was created using linear regression of egg masses across a range of sizes and relating egg number to relate egg mass weight or volume. Once the linear equation was developed, it was validated with a new set of egg masses of varying sizes. Egg mass volume and weight were positively correlated to the number of eggs deposited in an egg mass, and either can be used to estimate the number of eggs within egg masses. Finally, I investigated the use of black soldier fly processing residue (residual wastes, shed exoskeletons, and frass) as a fertilizer for an economic value-added product. Tomato seeds were planted in an inert growing media (coconut coir) with three concentrations of the processing residue and compared to a control of slow-release fertilizer. The two highest concentrations of black soldier fly processing residue resulted in failed germination, whereas the lowest concentration supported germination and growth with larger root and shoot biomass, larger leaf area, and a higher number of flowering trusses compared to the slow-release fertilizer treatment. Together, my research provides valuable new insight into the black soldier fly’s waste conversion ability, an essential tool for commercially-scalable methods of quantifying egg numbers in a non-destructive and timely manner that allows the establishment of optimized feed rates for the black soldier fly in waste management, and a useful end product to promote a circular economy

    XIII International Congress in Animal Hygiene, June 17-21, 2007, Tartu, Estonia "Animal health, animal welfare and biosecurity" : proceedings. Volume 1

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    KonverentsikogumikOn behalf of both the Organising Committee and the Scientific Committee, I am pleased to welcome you in Tartu, Estonia, to participate at the XIII International Congress of the International Society for Animal Hygiene (ISAH). The ISAH (www.isah-soc.org) was founded in 1970 and has today members from 48 countries throughout the world. ISAH can be considered as a group of scientists contributing to efficient, sustainable animal farming with healthy animals, providing wholesome food in a sound environment. Veterinarians and non-veterinary academic scientists (animal science, agricultural economics, engineers, microbiologists, public health professionals, epidemiologists etc., etc) and respective professionals in animal husbandry, who work and/or do research and education in the field of animal hygiene, can apply for a membership of ISAH, and are most welcome to attend ISAH congresses. The first ISAH congress was held in Budapest in 1973. The last ISAH main congress took place in Warsaw, Poland in 2005 and the last in-between symposium in Saint-Malo, France in 2004. Starting from Warsaw congress in 2005, the ISAH, considering the need for a more flexible and frequent exchange of scientific and practical knowledge, organizes its congresses every second year. The present, XIII ISAH congress in Tartu, Estonia, in June 17–21, 2007 is organised under the device "Animal health, animal welfare and biosecurity”. The scientific programme, trying to follow the scope of the ISAH and receive the feedback from modern animal husbandry and food production, concentrates with more profoundness on the following subjects: interaction between the environment and health and welfare of individual animal and herds; managing animal health in large dairy units; ensuring animal welfare during transportation and slaughter; economical implications considering animals’ health; possibilities of precision livestock farming in maintaining good health and welfare of animals; measures for prevention the development and spread of diseases and pathogens in animals including those posing risk to human health (zoonoses); food safety relevant infections and contaminations such as residues in food derived from animals; influence of the animal production on the environment and public health. The Proceedings from the XIII ISAH Congress are herewith presented. The papers on lectures from invited speakers, oral and poster presentations from 11 parallel sessions are included in this excellent compilation. In general, the printed contribution to the ISAH-2007 congress illustrates clearly the broad scientific field of the ISAH and related to it activities. I hereby would like to express my most sincere gratitude in the address of ISAH-2007 organising and scientific committees. Special thanks go to Frens Conference Services for their excellent organizational and technical contribution and to AS Triip for their outstanding printing job of these proceedings. We also appreciate different companies and organisations for their considerable financial support which gave us the opportunity to keep the registration fees affordable. Finally, we thank all participants, contributors, chairpersons, organisational and technical assistants for your considerable efforts – you made the ISAH-2007 in Tartu real success. We wish you all interesting and pleasant congress and enjoyable stay in Tartu. A. Aland Editor Chairman of the ISAH-2007 Organising Committe

    Molecular phylogeny of horseshoe crab using mitochondrial Cox1 gene as a benchmark sequence

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    An effort to assess the utility of 650 bp Cytochrome C oxidase subunit I (DNA barcode) gene in delineating the members horseshoe crabs (Family: xiphosura) with closely related sister taxa was made. A total of 33 sequences were extracted from National Center for Biotechnological Information (NCBI) which include horseshoe crabs, beetles, common crabs and scorpion sequences. Constructed phylogram showed beetles are closely related with horseshoe crabs than common crabs. Scorpion spp were distantly related to xiphosurans. Phylogram and observed genetic distance (GD) date were also revealed that Limulus polyphemus was closely related with Tachypleus tridentatus than with T.gigas. Carcinoscorpius rotundicauda was distantly related with L.polyphemus. The observed mean Genetic Distance (GD) value was higher in 3rd codon position in all the selected group of organisms. Among the horseshoe crabs high GC content was observed in L.polyphemus (38.32%) and lowest was observed in T.tridentatus (32.35%). We conclude that COI sequencing (barcoding) could be used in identifying and delineating evolutionary relatedness with closely related specie

    Crab and cockle shells as heterogeneous catalysts in the production of biodiesel

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    In the present study, the waste crab and cockle shells were utilized as source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shells are calcium carbonate which transformed into calcium oxide upon activated above 700 °C for 2 h. Parametric studies have been investigated and optimal conditions were found to be catalyst amount, 5 wt.% and methanol/oil mass ratio, 0.5:1. The waste catalysts perform equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to five times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity
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