3,681 research outputs found
Characterization of fruit and vegetable wastes as a single substrate for the anaerobic digestion
No full textAnaerobic digestion of potato industry by-products on a pilot-scale plant under thermophilic conditions
No full textEnergy-oriented optimization of an anaerobic digestion plant for the combined treatment of solid and liquid wastes in a potato chips industrial plant
No full textPotato chips represent the main product of the snack food industry. Their processing determines the production of several kinds of wastes characterised by different physical and chemical properties that make them eligible feedstock for biological treatments. In this paper the anaerobic digestion of all the solid and liquid wastes, produced by a potato chips processing line and properly mixed, is investigated. The experiment hereby described is carried out on a pilot-scale plant and aims to reproduce the real situation of a potato chips factory by feeding all the wastes in the anaerobic reactor in a ratio suitable for an effective treatment process. A comparison between the performance of anaerobic digestion processes feed by raw potato wastes and balanced mixtures of all potato wastes deriving from potato chips processing lines is carried out. Finally, the results of the experimental investigation were used for a preliminary performance evaluation of a full-scale anaerobic digestion power plant for treating all the potato wastes produced by an industrial potato chips production plant
Application of GAB or other models for water sorption isotherms determination of traditional bakery products
No full textEnergy performance assessment of mesophilic anaerobic digestion of fruit and vegetable wastes in a pilot-scale reactor
No full textThe main aim of the study presented in this paper was to evaluate the energy performance of anaerobic digestion of fruit and vegetable wastes (FVW) on a pilot scale in mesophilic conditions (35 °C), without the addition of any other kind of co-substrate. The anaerobic digestion experiment was carried out in a semi-continuous tubular horizontal reactor (1.13 m3) and lasted 6 months to take into account all the possible changes in feedstock composition during different periods of the year. Throughout the experiment the feedstock was characterized by measuring the total solid content, volatile solid content and higher heating value. The composition and energy contents of the biogas produced and the residue sludge were also evaluated. The results of the study demonstrate that fruit and vegetable wastes lead to high biogas yields and high methane contents. In particular, an average biogas yield of 0.80 Nm3 /kgvs and a specific methane yield of 0.45 Nm3 /kgvs were obtained. Since biogas is mainly used for energy production, a cumulative calculation of the energy content of feedstock, biogas and digestate during the whole experiment was carried out. At the end of the experimental period the energy content of the biogas produced was about 60% of the feedstock energy input, the residual energy content of the digestate was 15%, while the remaining 25% was the energy content of the biomass contained within the reactor. Energy conversion efficiency increases to about 80% by taking into account the biogas that would be produced by the biomass contained within the reactor. It is very interesting to note that the energy content of the reactor remains almost constant when the steady state is completely reached
Biogas from anaerobic digestion of fruit and vegetable wastes: experimental results on pilot-scale and preliminary performance evaluation of a full-scale power plant
No full textThis paper presents the experimental results obtained through an anaerobic digestion pilot plant by using fruit and vegetable wastes as single substrate. The substrate materials were sampled from the wastes produced by the Fruit and Vegetable Wholesale Market of Sardinia (Italy).
The experimental study was carried out over a period of about six months to evaluate the most suitable operating parameters of the process depending on the availability of different kinds of fruit and vegetable wastes over the different periods of the year. Overall, the optimum daily loading rate of wastes was 35 kg/d, with a corresponding hydraulic residence time of 27 days. The optimum organic loading rate ranged from 2.5 to 3.0 kgVS/m3d and the average specific biogas production was about 0.78 Nm3/kgVS, with a specific methane yield of about 0.43 Nm3/kgVS.
The results of the experimental investigation were used for a preliminary performance evaluation of a full-scale anaerobic digestion power plant for treating all the fruit and vegetable wastes produced by the Wholesale Market of Sardinia (9 t/d). The estimate of daily methane production (290 Nm3/d) leads to a CHP unit with a power output of about 42 kW and an annual electrical production of about 300 MWh/y (about 25% of the wholesale market electrical consumption). The AD power plant also shows interesting economic features, since its energy production cost (about 150 €/MWh) is slightly lower than the energy purchase cost of the wholesale market (about 200 €/MWh) and a pay-back time of about 7.25 years can be achieved in the case of dispatching the electrical energy to the national grid. The PBT decreases to about 5.4 years if 50% of the available thermal energy is used to substitute heat production from fossil fuel boilers.
Keywords
Anaerobic digestion; fruit and vegetable waste; biogas production; mesophilic digestion
Emotional availability (EA) teleintervention for adoptive families
No full text2012 Fall.Includes bibliographical references.This study evaluated the new online Emotional Availability (EA) Intervention for use with adoptive families in enhancing parent-child EA, parental perceptions of EA, child attachment behaviors, parent-child emotional attachment, and reducing parent-reported child behavioral problems and parenting-related stress. Participants in this study were adoptive parents and their adopted children ages 1.5 - 5 years old (N = 15 dyads). Participants were placed in an immediate intervention group (IG) or a delayed intervention group (DG) that would receive the 6-week EA Intervention after the IG. Results revealed significant differences in the IG in child behavioral problems, parent-child EA, parental perceptions of EA, and parent-child emotional attachment, improvements not seen in the DG. Analysis of effects of the DG after receiving the EA Intervention revealed significant differences over time also in child behavioral problems, parent-child EA, parental perceptions of EA, and parent-child emotional attachment. Implications, limitations, and future directions are discussed
Environmental (waste) compliance control systems for UK SMEs
No full textWhile the ‘environment’ is often perceived as a heavily regulated area of business, in reality, directly-regulated businesses represent a small proportion of the business community. This study aimed to evaluate and outline potential improvements to compliance controls for small and medium-sized enterprises (SMEs), particularly those involved in the waste sector. Forty-four SMEs from England were interviewed/audited between April-September 2008. Using a UK-based system as a case-in-point, the Environment Agency’s (EA) Operational Risk Appraisal (‘Opra’)/Compliance Assessment Report (CAR) system was analysed. Environmental compliance performance indicators and an initial assessment methodology for SMEs were developed. The study showed:• Compliance with permitting legislation was poor in many areas.• Regulatory authorities are either unable/failing to implement their enforcement policies or unable/failing to identify non-compliances due to the infrequency or limited nature of their inspections.• Improvements are needed to the EA Opra/CAR system – control measures are not fully taken into account when calculating risk.Recommendations to improve SME compliance controls include using internationally applicable general and specific compliance and non-compliance performance indicators, re-designing the Opra system and using an initial assessment methodology based on understanding the hazardousness of SME categories, compliance levels and operator competency.<br/
Comparative genomic and transcriptomic analysis revealed genetic characteristics related to solvent formation and xylose utilization in <it>Clostridium acetobutylicum </it>EA 2018
No full textAbstract Background Clostridium acetobutylicum, a gram-positive and spore-forming anaerobe, is a major strain for the fermentative production of acetone, butanol and ethanol. But a previously isolated hyper-butanol producing strain C. acetobutylicum EA 2018 does not produce spores and has greater capability of solvent production, especially for butanol, than the type strain C. acetobutylicum ATCC 824. Results Complete genome of C. acetobutylicum EA 2018 was sequenced using Roche 454 pyrosequencing. Genomic comparison with ATCC 824 identified many variations which may contribute to the hyper-butanol producing characteristics in the EA 2018 strain, including a total of 46 deletion sites and 26 insertion sites. In addition, transcriptomic profiling of gene expression in EA 2018 relative to that of ATCC824 revealed expression-level changes of several key genes related to solvent formation. For example, spo0A and adhEII have higher expression level, and most of the acid formation related genes have lower expression level in EA 2018. Interestingly, the results also showed that the variation in CEA_G2622 (CAC2613 in ATCC 824), a putative transcriptional regulator involved in xylose utilization, might accelerate utilization of substrate xylose. Conclusions Comparative analysis of C. acetobutylicum hyper-butanol producing strain EA 2018 and type strain ATCC 824 at both genomic and transcriptomic levels, for the first time, provides molecular-level understanding of non-sporulation, higher solvent production and enhanced xylose utilization in the mutant EA 2018. The information could be valuable for further genetic modification of C. acetobutylicum for more effective butanol production.</p
Navigating Enterprise Architecture (EA) Institutionalization: The Interplay of EA and Agile
No full textIn the rapidly evolving context of digital transformation, the effective adoption, management, and institutionalization of Enterprise Architecture (EA) have emerged as significant efforts for organizations looking for ways to navigate the complex requirements of modern business environments. This Ph.D. thesis embarks on a comprehensive exploration of different aspects of EA, ranging from its adoption challenges to its interaction with agile transformations. This study's main objective is to shed light on different aspects of EA adoption, management, challenges, and integration within large-scale organizations.
The research questions that form the foundation of this thesis are designed to explore the complex nuances of an EA's journey within an organization. The thesis investigates the role of stakeholders in influencing the perception and institutionalization of EA in order to respond to the first research question. It highlights the complex interactions between different stakeholders and their different interests, showing how these interactions can have a big impact on how successful EA initiatives are. The study goes deeper into the organizational factors that contributed to the failure of EA management initiatives, explaining the significance of legitimacy and showing challenges to achieving normative and cultural-cognitive legitimacy.
The third research question focuses on the topic of delegitimization of established EA practices. The thesis shows the ways through which EA practices can lose momentum and relevance within organizations by examining the complex interplay of regulatory, pragmatic, normative, and cultural-cognitive legitimacy. Building on this foundation, the thesis navigates the cycles of EA's institutionalization, de-institutionalization, and re-institutionalization within the organizational context. This dynamic approach highlights the importance of regaining legitimacy and adapting to modern organizational approaches in order to achieve successful re-institutionalization.
In light of the growing popularity of agile approaches, the thesis investigates the challenges posed by such paradigm shifts to established EA practices. The study outlines the modifications that must be made to EA practices by identifying the main functions that EA must do to support organizational agility. The outcome of this study is a collection of five papers, each of which shows a different part of EA's journey. Together, these contributions enhance the understanding of EA's adoption, management, and integration with agile paradigms, significantly advancing the body of knowledge in this domain.
This Ph.D. thesis gives a comprehensive overview of EA's strategic, operational, and innovative capacity. It shows how stakeholders, organizational dynamics, and an evolving digital environment all work together. This thesis helps organizations looking to use the advantages of EA in their goals of sustainable growth and agility by addressing the research questions and highlighting different aspects of the EA's role.Fulltext not availabl
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