92 research outputs found
An Integrated Waste Management Process: Integrating Hydrothermal Carbonisation with Anaerobic Digestion for Opportunities to Valorise Digestate and Waste Biomass
In the last decade, significant growth exhibited by the organic waste management industry in the UK has begun to decline due to removal of incentives, reduced material availability due to competition and implementation of quality standards for environmental regulation. Therefore, the purpose of this thesis is to provide a proof of concept for a novel approach to integrating biomass conversion technologies for improved organic waste management, maximising energy recovery and accelerating the process of composting. Specifically, the research aim is to identify the potential opportunities for the integration of hydrothermal carbonisation (HTC) with anaerobic digestion (AD) to treat and valorise digestate and green waste materials.
AD operators competing for feedstock often accept contaminated wastes which produce digestate that does not meet the quality specification for application as a fertiliser. As a result, operational expenses increase due to storage, transport and gate fees required for the disposal of digestate. Digestate, when applied to land also gives rise to concerns about eutrophication and fugitive greenhouse gas emissions. Additionally, the emissions generated from the composting of green wastes are not captured. Furthermore, if these biomass materials are not utilised as an agricultural product the nutrients they hold are lost, unless they are recycled. Literature has highlighted several key development areas within the AD industry aimed at decreasing the operating costs of digestion facilities. Digestate enhancement technologies, such as HTC and pyrolysis thermochemical processing, have been recognised for treating and increasing the value of digestate to secure use and create new markets. However, a significant gap in the literature, which this thesis intends to fill, lies in comparing thermochemical technologies, experimentation on a range of digestate materials and assessment of the application of products generated. Synthesis of this study’s findings show that the aim and objectives of the study have been met. Opportunities for valorisation lie in enhanced biogas generation from the recirculation of HTC process waters into AD and the use of hydrochar as a soil amender. Furthermore, the integration approach also introduces alternative recalcitrant AD feedstock via HTC pre-treatment which allows for acceleration of solubilisation and the humification process, whilst mitigating greenhouse gas emissions.
Chapter-specific results show that composition analysis of the feedstock materials demonstrate digestate and green waste have considerable energy recovery potential, due to high fractions of protein and lignocellulose respectively. The application of HTC process waters via AD generates bio-methane owing to the high concentrations of soluble organic compounds, particularly from high biodegradable process waters from the HTC of sewage sludge digestate and grass clippings at 200 °C. Hydrochar, when applied in agriculture as a soil amender has the potential as a slow release fertiliser due to improvements in fresh plant mass yields owing to being humic like and exhibiting good macro and micro nutrient content, especially from sewage sludge digestate. Furthermore, hydrochar and pyrochar converted from digestate materials are not suitable as a solid fuel due to high inorganic content and low energy density, resulting in very likely slagging and fouling propensity. However, high temperature 250 °C HTC co-processing by blending with green wastes, particularly woodchip, increases calorific values (up to 20 MJ per kg), energy density (up to a factor of 1.2) and reduces inorganic concentrations (by up to 50 percent), improving solid fuel properties. It was also found that the enhancement of digestate via pyrolysis is not favourable due to requirements of dewatering digestate, low liquid yields and high slagging and fouling potential of pyrochar as a solid fuel. HTC is more suitable for waste biomass treatment as it promotes demineralisation and solubilises organic compounds.
The significance of this study will benefit the circular economy and aids in reaching climate change targets from the generation of renewable energy and production of hydrochar that locks in carbon and provides benefits to agriculture. This is especially important in terms of reducing fossil fuel use and its impacts on soil erosion and fertility. The contributions of this thesis will be of interest to researchers in the fields of microbiology and chemical processing for the production of bio-hydrogen, bio-alcohols and fine chemicals from the fermentation of HTC process water. Soil scientists will also be interested in the potential of hydrochar applied in agriculture for remediation and soil amelioration. Moreover, researchers in the field of energy and storage will be interested in the combustion and electrical storage potential of hydrochar
A Systematic Review and Comparative Meta-analysis of Non-destructive Fruit Maturity Detection Techniques
The global fruit industry is growing rapidly due to increased awareness of the health benefits associated with fruit consumption. Fruit maturity detection plays a crucial role in fruit logistics and maintenance, enabling farmers and fruit industries to grade fruits and develop sustainable policies for enhanced profitability and service quality. Non-destructive fruit maturity detection methods have gained significant attention, especially with advancements in machine vision and spectroscopic techniques. This systematic review provides a concise overview of the techniques and algorithms used in fruit quality grading by farmers and industries. The study reviewed 63 full-text articles published between 2012 and 2023 along with their bibliometric analysis. Qualitative analysis revealed that researchers from various disciplines contributed to this field, with techniques falling into 3 categories: machine vision (mathematical modelling or deep learning), spectroscopy and other miscellaneous approaches. There was a high level of diversity among these categories, as indicated by an I-square value of 88.37% in the heterogeneity analysis. Meta-analysis, using odds ratios as the effect measure, established the relationship between techniques and their accuracy. Machine vision showed a positive correlation with accuracy across different categories. Additionally, Egger's and Begg's tests were used to assess publication bias and no strong evidence of its occurrence was found. This study offers valuable insights into the advantages and limitations of various fruit maturity detection techniques. For employing statistical and meta-analytical methods, key factors such as accuracy and sample size have been considered. These findings will aid in the development of effective strategies for fruit quality assessment
Haemostatic Changes in Five Patients Infected with Ebola Virus
Knowledge on haemostatic changes in humans infected with Ebola virus is limited due to safety concerns and access to patient samples. Ethical approval was obtained to collect plasma samples from patients in Sierra Leone infected with Ebola virus over time and samples were analysed for clotting time, fibrinogen, and D-dimer levels. Plasma from healthy volunteers was also collected by two methods to determine effect of centrifugation on test results as blood collected in Sierra Leone was not centrifuged. Collecting plasma without centrifugation only affected D-dimer values. Patients with Ebola virus disease had higher PT and APTT and D-dimer values than healthy humans with plasma collected in the same manner. Fibrinogen levels in patients with Ebola virus disease were normal or lower than values measured in healthy people. Clotting times and D-dimer levels were elevated during infection with Ebola virus but return to normal over time in patients that survived and therefore could be considered prognostic. Informative data can be obtained from plasma collected without centrifugation which could improve patient monitoring in hazardous environment
Haemostatic Changes in Five Patients Infected with Ebola Virus
Knowledge on haemostatic changes in humans infected with Ebola virus is limited due to safety concerns and access to patient samples. Ethical approval was obtained to collect plasma samples from patients in Sierra Leone infected with Ebola virus over time and samples were analysed for clotting time, fibrinogen, and D-dimer levels. Plasma from healthy volunteers was also collected by two methods to determine effect of centrifugation on test results as blood collected in Sierra Leone was not centrifuged. Collecting plasma without centrifugation only affected D-dimer values. Patients with Ebola virus disease had higher PT and APTT and D-dimer values than healthy humans with plasma collected in the same manner. Fibrinogen levels in patients with Ebola virus disease were normal or lower than values measured in healthy people. Clotting times and D-dimer levels were elevated during infection with Ebola virus but return to normal over time in patients that survived and therefore could be considered prognostic. Informative data can be obtained from plasma collected without centrifugation which could improve patient monitoring in hazardous environment
Qualification study of SiPMs on a large scale for the CMVD Experiment
A Cosmic Muon Veto (CMV) detector using extruded plastic scintillators is
being designed around the mini-Iron Calorimeter (mini-ICAL) detector at the
transit campus of the India based Neutrino Observatory, Madurai for the
feasibility study of shallow depth underground experiments. The scintillation
signals that are produced in the plastic due to muon trajectories are absorbed
by wavelength shifting (WLS) fibres. The WLS fibres re-emit photons of longer
wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs
detect these photons, producing electronic signals. The CMV detector will use
more than 700 scintillators to cover the mini-ICAL detector and will require
around 3000 SiPMs. The design goal for the cosmic muon veto efficiency of the
CMV is >99.99%. Hence, every SiPM used in the detector needs to be tested and
characterised to satisfy the design goal of CMV. A mass testing system was
developed for the measurement of gain and choice of the overvoltage ()
of each SiPMs using an LED driver. The is obtained by studying the
noise rate, the gain of the SiPM. This paper describes the experimental setup
used to test the SiPMs characteristics along with detailed studies of those
characteristics as a function of temperature.Comment: 16 pages, 20 figure
Global 30-day outcomes after bariatric surgery during the COVID-19 pandemic (GENEVA): an international cohort study
Health, education, and social care provision after diagnosis of childhood visual disability
Aim: To investigate the health, education, and social care provision for children newly diagnosed with visual disability.Method: This was a national prospective study, the British Childhood Visual Impairment and Blindness Study 2 (BCVIS2), ascertaining new diagnoses of visual impairment or severe visual impairment and blindness (SVIBL), or equivalent vi-sion. Data collection was performed by managing clinicians up to 1-year follow-up, and included health and developmental needs, and health, education, and social care provision.Results: BCVIS2 identified 784 children newly diagnosed with visual impairment/SVIBL (313 with visual impairment, 471 with SVIBL). Most children had associated systemic disorders (559 [71%], 167 [54%] with visual impairment, and 392 [84%] with SVIBL). Care from multidisciplinary teams was provided for 549 children (70%). Two-thirds (515) had not received an Education, Health, and Care Plan (EHCP). Fewer children with visual impairment had seen a specialist teacher (SVIBL 35%, visual impairment 28%, χ2p < 0.001), or had an EHCP (11% vs 7%, χ2p < 0 . 01).Interpretation: Families need additional support from managing clinicians to access recommended complex interventions such as the use of multidisciplinary teams and educational support. This need is pressing, as the population of children with visual impairment/SVIBL is expected to grow in size and complexity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
Prevalence and factors associated with tuberculosis infection in India
Background: The risk of tuberculosis (TB) disease is higher in individuals with TB infection. In a TB endemic country like India, it is essential to understand the current burden of TB infection at the population level. The objective of the present analysis is to estimate the prevalence of TB infection in India and to explore the factors associated with TB infection. Methods: Individuals aged > 15 years in the recently completed National TB prevalence survey in India who were tested for TB infection by QuantiFERON-TB Gold Plus (QFT-Plus) assay were considered for this sub- analysis. TB infection was defined as positive by QFT-Plus (value > 0.35 IU/ml). The estimates for prevalence, prevalence ratio (PR) and adjusted risk ratio (aRR) estimates with 95% confidence intervals (CIs) were calculated. Results: Of the 16864 individuals analysed, the prevalence of TB infection was 22.6% (95% CI:19.4 −25.8). Factors more likely to be associated with TB infection include age > 30 years (aRR:1.49;95% CI:1.29–1.73), being male (aRR:1.26; 95%CI: 1.18–1.34), residing in urban location (aRR:1.58; 95%CI: 1.03–2.43) and past history of TB (aRR:1.49; 95%CI: 1.26–1.76). Conclusion: About one fourth (22.6%) of the individuals were infected with TB in India. Individuals aged > 30 years, males, residing in urban location, and those with past history of TB were more likely to have TB infection. Targeted interventions for prevention of TB and close monitoring are essential to reduce the burden of TB in India
30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data
Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts
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