Bioproduction of Acetic Acid From Carbon Dioxide as Single Substrate and Zero Valent Iron (ZVI) by Clostridia

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Developing innovative bioprocess strategies for carbon capture and utilization has been a major focus of research over the past decade as a way of creating a more resilient world. In this study, zero-valent iron (ZVI) was utilized to generate hydrogen, which was then utilized as an electron donor for CO2 reduction by either Clostridium aceticum or Clostridium carboxidivorans. For this bioprocess, an early acidic condition in the reactors facilitated more hydrogen production and thereby more acetic acid accumulation, in contrast to later acidification, elucidating the role of pH in ZVI-CO2 bioconversion. Acetic acid was produced as single end product of the process in both batch bottle studies with no pH control as well as in reactor studies with pH regulation. This is, to the best of our knowledge, the first report on selective pure CO2 bioconversion to acetic acid by clostridia, with ZVI. In order to minimize costs, scrap iron rather than pure ZVI can be used for scaling-up. By lowering the pH to 6.6 for C. aceticum, in reactor studies with 75 g/L ZVI, some ethanol production (125 mg/L) was also observed, besides acetic acid. In reactor studies, a maximum acetic acid concentration of about 2 g/L was obtained at ZVI concentrations of 50 and 75 g/L. Thus, ZVI dosage and medium pH have a major effect on the metabolites generated during CO2 utilization.This research was partly financed by the Spanish Ministry of Science and Innovation Through Project PID2020-117805RB-I00 and European FEDER funds. BB thanks Xunta de Galicia for funding her predoctoral fellowship (ED481A-2020/226) to undertake research at the BIOENGIN group. The BIOENGIN group also thanks Xunta de Galicia for financial support to Competitive Reference Research Groups (ED431C 2021/55). Funding for open access charge provided by Universidade da Coruña/CISUGXunta de Galicia; ED481A-2020/226Xunta de Galicia; ED431C 2021/5

DECISION SUPPORT MODEL IN FAILURE-BASED COMPUTERIZED MAINTENANCE MANAGEMENT SYSTEM FOR SMALL AND MEDIUM INDUSTRIES

Maintenance decision support system is crucial to ensure maintainability and reliability of equipments in production lines. This thesis investigates a few decision support models to aid maintenance management activities in small and medium industries. In order to improve the reliability of resources in production lines, this study introduces a conceptual framework to be used in failure-based maintenance. Maintenance strategies are identified using the Decision-Making Grid model, based on two important factors, including the machines’ downtimes and their frequency of failures. The machines are categorized into three downtime criterions and frequency of failures, which are high, medium and low. This research derived a formula based on maintenance cost, to re-position the machines prior to Decision-Making Grid analysis. Subsequently, the formula on clustering analysis in the Decision-Making Grid model is improved to solve multiple-criteria problem. This research work also introduced a formula to estimate contractor’s response and repair time. The estimates are used as input parameters in the Analytical Hierarchy Process model. The decisions were synthesized using models based on the contractors’ technical skills such as experience in maintenance, skill to diagnose machines and ability to take prompt action during troubleshooting activities. Another important criteria considered in the Analytical Hierarchy Process is the business principles of the contractors, which includes the maintenance quality, tools, equipments and enthusiasm in problem-solving. The raw data collected through observation, interviews and surveys in the case studies to understand some risk factors in small and medium food processing industries. The risk factors are analysed with the Ishikawa Fishbone diagram to reveal delay time in machinery maintenance. The experimental studies are conducted using maintenance records in food processing industries. The Decision Making Grid model can detect the top ten worst production machines on the production lines. The Analytical Hierarchy Process model is used to rank the contractors and their best maintenance practice. This research recommends displaying the results on the production’s indicator boards and implements the strategies on the production shop floor. The proposed models can be used by decision makers to identify maintenance strategies and enhance competitiveness among contractors in failure-based maintenance. The models can be programmed as decision support sub-procedures in computerized maintenance management systems

Fifty Shades of Gray Infrastructure: Land Use and the Failure to Create Resilient Cities

Land use laws, such as comprehensive plans, site plan reviews, zoning, and building codes, greatly affect community resilience to climate change. One often-overlooked area of land use law that is essential to community resilience is the regulation of infrastructure on private property. These regulations set standards for infrastructure built by private developers. Such infrastructure is completed in conjunction with millions of commercial and residential projects and is necessary for critical services, including potable water and energy distribution. Throughout the fifty states, these land use laws regulating infrastructure constructed by private developers encourage or compel “gray infrastructure.” Marked by human-made, engineered solutions, including pipes, culverts, and detention basins, gray infrastructure reflects a desire to control, remove, and manipulate ecosystems. Left untouched, these ecosystems often provide critical services that strengthen a community’s resilience to disasters and slow changes. This Article describes the current state of land use laws and their focus on human-engineered, gray infrastructure developed as part of private projects. It explores how that infrastructure is reducing community resilience to change. By creatively combining human-engineered solutions with ecosystem services already available and by incorporating adaptive governance into the regulation of infrastructure erected by private parties, this Article describes how land use laws can enhance community resilience. The Article concludes with several examples where land use laws are relied upon to help build cost-effective, adaptive infrastructure to create more resilient communities

Ennustava kysyntäjousto kaukolämmitetyissä ja -jäähdytetyissä kiinteistöissä

Contemporary technologies enable the control of energy consumption in buildings in a way which minimizes costs and maximizes consumer comfort. Cost reductions have been seen in District Heating and Cooling systems mostly as energy conservation. On the other hand, consumer comfort is increased by providing steadier indoor temperatures. Lately, literature present has presented a more agile approach of reducing costs by optimizing the consumption of the overall system with Demand-side Management. This approach aims to shift loads from peak load hours without necessarily reducing energy consumption. This thesis provides a model which applies the thermal capacity of District Heating and Cooling connected buildings as thermal energy storages. An artificial District Heating system with variable production costs was developed for the model in order to form dynamic price signals. These signals were utilized in two simulations. The first optimized existing heat load data from heavy mass buildings to appraise the effect of Demand-side Management, whereas the second modelled the behaviour of individual rooms. Both simulations aimed to store heat beforehand in the building envelope and to discharge it during price peaks. This offered the possibility to consume heating energy based on individual consumption profiles and only take action when the whole system requires it. The simulation model indicates that predictive Demand-side Management with dynamic price signals reduces heating costs in buildings by 4% during the heating period. The main cost savings occur to energy producers since variable production costs can be decreased by 6% due to load control using 15% of the building stock’s heated floor area. The room simulation demonstrated that the building components are able to store heat dynamically by intelligent prediction of occupancy, outside weather, and prices. With an autonomous auction platform, Demand-side Management activities can be targeted to buildings which are most suitable to shift demand. The order of building participation is determined by individual consumer comfort and thermal dissipation. As predictive Demand-side Management relies on dynamic pricing and engagement of District Heating and Cooling customers and producers, the thesis proposes a concept to achieve a win-win situation for these stakeholders. In order to ensure a reasonable allocation of benefits from Demand-side Management and provide a more accurate demand prediction, new business models could emerge. These models can challenge producers and customers to revalue District Heating and Cooling.Nykyaikaiset teknologiat mahdollistavat rakennuksen energiankulutuksen hallinnan tavalla, joka minimoi kustannuksia ja maksimoi kuluttajien mukavuutta. Kustannusten alentaminen on kaukolämmössä ja -jäähdytyksessä perinteisesti saavutettu energiansäästöllä. Kuluttajien mukavuutta on taas parannettu tasaisemmalla lämmönjakelulla. Viimeisten vuosien aikana tutkijat ovat esittäneet kysyntäjoustoa ketteränä tapana alentaa systeemitason kustannuksia. Kysyntäjousto pykii siirtämään ajallisesti osan tehon huippukuormista. Energiankulutusta ei välttämättä vähennetä. Tämä työ tarjoaa mallin, joka hyödyntää kaukolämmitteisten rakennusten lämpökapasiteettia energiavarastoina. Mallia varten on kehitetty kaukolämpöjärjestelmä, jonka antamat hintasignaalit perustuvat muuttuviin tuotantokustannuksiin. Näitä signaaleja hyödynnettiin kahdessa simulaatiossa. Ensimmäinen optimoi kuormia systeemitasolla siirtäen olemassa olevia kulutusprofiileja, kun taas toinen simulaatio käsitteli ihanteellista huonemallia. Molempien simulaatioiden tarkoituksena on varastoida lämpöä etukäteen rakenteisiin ja purkaa sitä hintapiikkien aikana. Toisin kuin aiemmissa tutkimuksissa, lämmönsäätimet reagoivat muuttuviin hintasignaaleihin. Tällä tavalla rakennukset kuluttivat lämmitysenergiaa käyttäjien yksilöllisten kulutusprofiilien mukaisesti, ja kysyntäjoustotoimenpiteisiin ryhdyttiin, kun koko järjestelmä sitä vaati. Simulointimalli osoitti, että ennustava kysyntäjousto voi alentaa rakennuksen lämmityskustannuksia 4% lämmityskauden aikana. Suurimmat kustannussäästöt koituvat energiantuottajille, sillä muuttuvat tuotantokustannukset laskivat simulaatiossa 6% käyttäen 15% rakennuskannan pinta-alasta hyödyksi. Huonesimulaatio osoitti, että rakennuksiin voi varastoida dynaamisesti lämpöä läsnäolon, sään ja hintojen älykkäällä ennustamisella. Itsenäisellä huutokauppa-alustalla kysyntäjouston toimintaa voidaan kohdistaa rakennuksiin, joilla on parhaimmat edellytykset siirtää hetkittäin lämmitystehoa. Tämä jako määräytyy kuluttajien mieltymysten ja rakennuksen lämpöhäviöiden mukaan. Koska ennakoivan kysyntäjouston täyden potentiaalin hyödyntäminen perustuu asiakkaiden sekä tuottajien sitoumukseen, tutkielma ehdottaa konseptia, jossa kaikki osapuolet hyötyvät kysyntäjoustosta. Tutkielmassa käy ilmi, että uusia liiketoimintamalleja voi syntyä varmistamaan kohtuullisen hyödynjaon ja parantamaan lämpökuormien ennustettavuutta. Nämä mallit voivat haastaa osapuolia löytämään uutta arvoa kaukolämmöstä ja -jäähdytyksestä

Securing Healthy Circular Material Flows In The Built Environment:

Multi-family buildings usually have a fixed subdivision in units with standard layouts. However, households are all different and change over time, as so do their needs and desires. With this in mind, the Open Building concept, which originated in the 1960s, proposed two levels of intervention and decision-making: the (collective) ‘support’ and (individual) ‘infill’. Although the Open Building approach has been embraced conceptually, with a new wave of interest in the Netherlands in recent years, it is remarkably overlooked in the actual design and construction of housing. The current attention for Circular Building puts, once again, the spotlight on Open Building. This renewed attention is due to the shared benefits around flexibility, and as such Circular Building and Open Building are two sides of the same coin. However, there is a big difference between accommodating unforeseen use of space and accommodating foreseen circularity-conditions for material management. Moreover, thus far little attention has been paid to residential user perspectives or the operational processes of Circular Building product and material cycles. Securing healthy circular material flows in the built environment cannot be the objective of one industry, let alone one organisation, but reshuffles whole value networks. This doctoral research adopts multiple perspectives and cuts through different scales and disciplines to derive criteria for indoor partitioning, with an emphasis on user health and well-being, flexibility and circularity. Although focused on partitioning, the findings can be applied to other components, such as kitchen cabinets, furniture, stairs, or to the interior side-sheeting and insulation of walls and ceilings in energy renovations

Securing Healthy Circular Material Flows In The Built Environment

Departing from two problem statements, one concerning circularity in the built environment and one concerning flexibility in the built environment, this dissertation sets out to answer two main research questions: – In an Open Building division of support and infill, to what extent can the infill contribute to sustainable circular material & product flows? – Which qualitative and quantitative criteria and preconditions are central to integrating the notions of user health & well-being, circularity, and flexibility in infill configurations? In view on these research questions, this dissertation revolves around multiple topics and disciplines, addressing material properties, material flows, product design, and user benefits, relating to a specific building component: non-bearing partitioning. The research follows a mixed-method approach, primarily qualitatively driven and supported by quantitative data and tools. Literature studies, workshops and expert consultations are applied throughout the trajectory to derive, test and adjust criteria, guidelines and design concepts. The dissertation is structured around four research chapters (each set-up as a separate academic article), preceded by a general introduction and background sketch, and followed by an overarching evaluation of the findings. The results from the first research chapter (Chapter 3) concern the distinction of various intrinsic and relational properties, as well as an inventory matrix based on building layers and material reutilisation routes. In the next chapter (Chapter 4), a first set of criteria is derived (Circ-Flex I) in order to integrate flexibility, circularity and user benefits. In Chapter 5, criteria are further elaborated, including assessment guidelines that pinpoint health, well-being, and operational performance (Circ- Flex II). The following chapter (Chapter 6) is aimed at design aspects: a design conceptualisation trajectory is laid out, applying design preconditions rooted in the criteria that were shaped in the preceding chapters. Furthermore, a novel flow analysis and modelling method is utilised with respect to secondary raw materials: the Activity-based Spatial Material Flow Analysis (AS-MFA). This stage revolves around materialisation and operational propositions for an innovative partitioning configuration of side-panel and insulation. The innovations are based on renewable material and reversible adhesive technologies. The following conclusions are derived from the research: Circularity in the built environment can only occur if flexibility is fully integrated in the whole building (component) value network, and conversely, flexibility in the built environment increasingly depends on the handling and management of materials designated for healthy, circular applications. – Infill parts, implemented in an Open Building context, enable multiple short to medium length cycles within the longer service lives of multi-family building structures, following changes in user requirements. As such, this model accommodates more sustainable product and material flows. However, decisive success factors are the attitude of and interplay between actors in the value network, not least the end-user. – Technical circularity potential of building products and materials resides at the intersection of intrinsic and relational characteristics. – The differentiation of building layers and parts, in combination with differentiated reutilisation routes, provides leverage for more advanced approaches to circular building strategies, anticipating multiple handling and treatment processes. – To bring circular building to scale in a socially engaged way, value models need to take account of actors’ shared incentives around flexibility and health, as well as split incentives around circularity. – Monitoring the operational performance is key for capitalising on the intrinsic health and circularity potential of building components during their service life. – Research and design exercises into circular building concepts and products benefit reciprocally from data and experience in adjacent disciplines, such as urban planning and waste management, whilst integrating multiple sub-systems associated with value creation in circular models. – Modifications associated with the innovative partition concepts occur above all in raw material sourcing, manufacturing, reutilisation logistics, and data-sharing, of which the latter should extend to the end-user. Next to partitioning, the findings can be relevant for other infill components as well, such as: kitchen cabinets, stairs, furniture, and the interior side-sheeting and insulation of walls and ceilings in energy-renovations. Follow-up research and practical efforts should be aimed at the development and testing of products, as well as value propositions regarding ownership: from regular transactions in which ownership shifts to the customer, to more innovative models in which ownership stays with the supplier or shifts to an intermediary actor (e.g. pay-per-use, buy-back or deposit model). Securing healthy circular material flows in the built environment cannot be the objective of one industry, let alone one organisation, but reshuffles whole value networks. This cannot be done without binding agreements and multi‑criteria learning loops. The first emphasises legal frameworks. This is therefore another prime area for future action. The aspect of multi-criteria learning loops, finally, relates to the need for more sophisticated data-exchange, also engaging endusers, which is nowadays rare in housing