Development of a fuzzy qualitative risk assessment model applied to construction industry

Dissertação para obtenção do Grau de Doutor em Engenharia IndustrialThe construction industry is plagued by occupational risky situations and poor working conditions. Risk Assessment for Occupational Safety (RAOS) is the first and key step to achieve adequate safety levels, particularly to support decision-making in safety programs. Most construction safety efforts are applied informally under the premise that simply allocating more resources to safety management will improve safety on site. Moreover, there are many traditional methods to address RAOS, but few have been adapted and validated for use in the construction industry, thus producing poor results. The contribution of this dissertation is a qualitative fuzzy RAOS model, tailored for the construction industry, named QRAM (Qualitative Risk Assessment Model). QRAM is based on four dimensions: Safety Climate Adequacy, (work accidents) Severity Factors, (work accidents) Possibility Factors and Safety Barriers Effectiveness. The risk assessment is based on real data collected by observation of reality, interviews with workers, foreman and engineers and consultation of site documents (working procedures, reports of work accident investigation, etc.), avoiding the use of data obtained by statistical tecnhiques. To rating each parameter it was defined qualitative evaluators - linguistic variables - which allow to perform a user-friendly knowledge elicitation. QRAM was, firstly evaluated by “peer” review, with 12 safety experts from Brazil (2), Bulgaria (1), Greece (3), Turkey (3) and Portugal (3), and then, evaluated by comparing QRAM with other RAOS tecnhiques and methods. The safety experts , concluded that: a) QRAM is a versatile tool for occupational safety risk assessment on construction sites; b) the specific checklists for knowledge elicitation are a good decision aid and, c) the use of linguistic variables is a better way to make the risk assessments process more objective and reliable.Fundação para a Ciência e Tecnologia - PhD Scholarship SFRH/BD/39610/200

Agroforestry as a post-mining land-use approach for waste deposits in alluvial gold mining areas of Colombia

Alluvial gold mining generates a vast amount of extractive waste that completely covers the natural soil, destroys riparian ecosystems, and negatively impacts river beds and valleys. Since 2002, a gold mining company has striven to create agroforestry plots in the waste deposits as a post-mining management approach, where agricultural crops and livestock are combined to complement reforestation in the area. This research aims at supporting reclamation of waste deposits by providing a comprehensive understanding of processes to manage the transition of nutrient-poor and acidic deposition sites towards productive agroforestry-based systems. Major components of this research comprise (i) an analysis of environmental and social challenges of the gold mining sector in Colombia, and its potential opportunities to add value to affected communities, (ii) an assessment of management practices and decision-making processes of the farmers working on reclamation areas, (iii) an analysis of the sources of variability of waste deposits from the perspective of soil development and vegetation succession, (iv) an analysis of spatial variability of the physicochemical properties of waste deposits with a spatially explicit management scheme, and (v) an assessment of vegetation recovery in terms of biomass and plant community composition. Farmers who are currently working on areas undergoing reclamation rely mostly on their own local knowledge to respond to the challenges that the heavily disturbed conditions of the area pose to crop establishment. Therefore, increasing their awareness of the inherent heterogeneity of their fields, as well as the interdependencies between management practices and improvement of soil fertility, may increase the productivity of their farms. The analysis of sources of variability of the waste deposits generated by alluvial gold mining revealed that these deposits are primarily influenced by the parent material of the alluvial gold deposits and by the technology used for gold mining (bucket or suction dredges), which define the type of deposit formed (gravel or sand). Waste deposits can provide essential functions for rural areas such as woody biomass production and crop establishment if deposits are managed according to a specific purpose, and crop selection for each deposit is done based on physicochemical and structural soil properties. This finding is echoed by the spatial assessment of vegetation reestablishment through the combination of remote sensing with machine-learning techniques that show a high spatial variability of textural properties and nutrient contents of the deposits. A management approach is proposed with the use of delineated management zones, which can lead to an overall increased productivity by developing strategies suitable to the characteristics of each field and its potential uses.Agroforstwirtschaft als Landnutzungsansatz auf Abraumdeponien in alluvialen Goldabbaugebieten Kolumbiens Der Abbau von alluvialem Gold erzeugt eine große Menge mineralischen Abfalls, der den natürlichen Boden vollständig bedeckt, Uferökosysteme zerstört, und Flussbetten und -täler negativ beeinflusst. Von einem Goldminenbetreiber werden seit 2002, als ein Ansatz einer Postbergbaustrategie, Agroforstparzellen in Abraumdeponien angelegt. In diesen werden landwirtschaftliche Nutzpflanzen und Viehhaltung zur Aufforstung der Parzelle kombiniert eingesetzt. Diese Forschungsarbeit beabsichtigt die Rekultivierungsmaßnahmen in Agroforstparzellen durch ein umfassendes Verständnis der beteiligten Prozesse zu unterstützen und den Übergang von nährstoffarmen und sauren Abraumdeponien hin zu produktiven agroforstbasierten Systemen zu steuern. Die Hauptbestandteile dieser Arbeit umfassen (i) eine Analyse der ökologischen und sozialen Herausforderungen des Goldminensektors in Kolumbien und potenzielle Möglichkeiten einen Mehrwert für die betroffenen Gemeinden zu schaffen, (ii) eine Bewertung der Managementpraktiken und Entscheidungsprozesse der Landwirte im Rahmen der Rückgewinnung von Landnutzungsflächen, (iii) eine Analyse der Ursachen von Varianz zwischen Abfalldeponien aus der Perspektive der Boden- und Vegetationsentwicklung, (iv) eine Analyse der räumlichen Variabilität der physikochemischen Eigenschaften von mineralischen Abraumdeponien mit einem räumlich expliziten Managementschema und (v) eine Bewertung der Vegetationserholung im Sinne der Zusammensetzung von Biomasse und Pflanzengemeinschaften. Landwirte die in Gebieten arbeiten die gegenwärtig einer Rekultivierung unterzogen werden, verlassen sich größtenteils auf ihre lokalen Erfahrungswerte, um mit den Herausforderungen für die Nutzpflanzenproduktion umzugehen, die durch die stark gestörten Bodenbedingungen verursacht werden. Eine Steigerung des Bewusstseins der lokalen Farmer für die inhärente Heterogenität ihrer Felder, sowie der Interdependenzen zwischen Managementpraktiken und der Verbesserung der Bodenfruchtbarkeit, kann die Produktivität der Farmbetriebe erhöhen. Die Analyse der Variabilitätsquellen der durch den alluvialen Goldabbau entstandenen mineralischen Abfalllager ergab, dass diese Lagerstätten in erster Linie vom Grundgestein der alluvialen Goldlagerstätten und der verwendeten Abbautechnik (Schaufel- oder Saugbagger) beeinflusst werden. Diese Faktoren bestimmen die Art der gebildeten Ablagerung (Kies oder Sand). Abfalldeponien können wesentliche Funktionen für ländliche Gebiete wie die Produktion von Holzbiomasse und den Anbau von Nutzpflanzen ermöglichen, wenn die Lagerstätten einem bestimmten Zweck entsprechend bewirtschaftet werden und die Auswahl der Kulturen für jede Lagerstätte auf Grundlage der spezifischen physikochemischen und strukturellen Bodeneigenschaften erfolgt. Dieser Befund wird durch die räumliche Bewertung der Vegetationsneubildung durch die Kombination von Fernerkundung mit maschinellen Lerntechniken bestätigt, die eine hohe räumliche Variabilität der Textureigenschaften und Nährstoffgehalte der Deponien zeigt. Es wird ein Managementansatz vorgeschlagen, bei dem abgegrenzte Bewirtschaftungszonen unterteilt werden. Dies kann zu einer insgesamt höheren Produktivität führen, indem Strategien entwickelt werden, die den Eigenschaften jedes einzelnen Feldes und seiner potenziellen Nutzungsmöglichkeiten entsprechen

Current Air Quality Issues

Air pollution is thus far one of the key environmental issues in urban areas. Comprehensive air quality plans are required to manage air pollution for a particular area. Consequently, air should be continuously sampled, monitored, and modeled to examine different action plans. Reviews and research papers describe air pollution in five main contexts: Monitoring, Modeling, Risk Assessment, Health, and Indoor Air Pollution. The book is recommended to experts interested in health and air pollution issues

Valuation of risk and complexity attributes causing delays in Australian Transport infrastructure projects for optimal contingency Estimation

The transportation projects have historically experienced significant delays and cost overruns from the time decision to build has been taken by the owner. This thesis addresses the problem of why this delay occurs by looking at the drivers from a risk management perspective. It identifies and analyses the owner risk attributes that contribute to significant delays related to transportation projects from an Australian context. After a literature review of current risks causing delays in transportation projects from across the globe, risk and complexity related to transport projects in Australia are identified from an Australian context using a questionnaire survey completed by participants with relevant experience in the transport industry. The risks are ranked using the Relative Importance Index (RII) based on likelihood and impact score. The results obtained include many attributes which are condensed to factors based on correlations using factor analysis. This gives us a big picture of the main risk and complexity factors affecting delays on transportation projects. Once done, a predictive model is obtained between the overall delay as the dependent variable and risk attributes as the independent variable. This is obtained using the statistical technique of Ordinal Multivariate regression. Lastly, a working framework that allows the methodology used in the thesis to be applied to all projects to understand the risk and complexity factors. This result can be useful for owners in obtaining a realistic design to build estimate in transport infrastructure projects by allocation of suitable contingency on risk and complexity drivers causing delays in transport infrastructure project

Energy Use Efficiency

Energy is one of the most important factors of production. Its efficient use is crucial for ensuring production and environmental quality. Unlike normal goods with supply management, energy is demand managed. Efficient energy use—or energy efficiency—aims to reduce the amount of energy required to provide products and services. Energy use efficiency can be achieved in situations such as housing, offices, industrial production, transport and agriculture as well as in public lighting and services. The use of energy can be reduced by using technology that is energy saving. This Special Issue is a collection of research on energy use efficiency

Building shared knowledge for EOR technologies: Screening guideline constructions, dashboards, and advanced data analysis

Successful implementation of enhanced oil recovery (EOR) technology requires comprehensive knowledge and experiences based on existing EOR projects. EOR screening guidelines and EOR reservoir analog are served as such knowledge which are considered as the first step for a reservoir engineer to determine the next step techniques to improve the ultimate oil recovery from their assets. The objective of this research work is to provide better assistance for EOR selection by using fundamental statistics methods and machine learning techniques. In this dissertation, a total of 977 worldwide EOR projects with the most uniformed, high-quality, and comprehensive information were collected from scattered publications and sources, which lays the foundation for further analysis and reasoning. Conventional screening guidelines for 12 EOR technologies were updated with the augment of critical parameters (e.g. MMP, net thickness) compared with previous studies. Hierarchical clustering and principal component analysis are applied for the construction of advanced EOR screening models. Furthermore, a hybrid EOR screening system was established with the combination of conventional and advanced screening technology. Finally, reservoir analog technology was applied to the steam flooding projects to detect the most similar case to assist the decision-making process with limited data information. The results show wider applicability from conventional guidelines; an advanced EOR selection model with discriminative screening results; a hybrid model which combines the advantages of conventional and advanced screening technologies; and an accurate reservoir analog results for steam flooding projects --Abstract, page iv

Sustainability and Safety Study of Tank to Propeller Process

Many public concerns have been brought to the increasingly intense greenhouse effects. The International Maritime Organization (IMO) has ambitious strategies to limit the air pollutant emissions from the merchant ships in a long run, especially for carbon, sulfur, methane and nitrogen oxides. To achieve IMO 2050 decarbonization objectives, more than one solution are required for maritime energy transition, from electric batteries for onboard activities to a variety of “green fuels” as well as safe and sustainable process design of onboard carbon capture, utilization, and storage (CCUS). Our work is focusing on screening promising marine fuels and providing safer and more sustainable carbon capture systems for maritime industry from the perspective of process safety and process systems engineering. This work can be divided into four major parts: Tank to propeller (TTP) sustainability study focuses on providing solutions on marine fuel consumption and TTP exhaust gas emission control, and a bottom-up emission inventory model was developed by analyzing and optimizing multiple parameters; Then an onboard carbon capture system called TTP post-combustion carbon capture (TTPPCC) system was proposed by integrating ship engine process modeling with chemical absorption/desorption process modeling techniques, this work covers a thorough sustainability evaluation based on emission reduction efficiency, energy penalty, and carbon cyclic capacity among two single aqueous amines, MEA and diisopropanolamine (DIPA), and one blended amine with a promoter, methyldiethanolamine (MDEA) with piperazine (PZ); The first TTP safety study aims at identifying the contributors influencing liquid aerosol flammability and solving their data deficiencies by developing quantitative structure−property relationship (QSPR) models, 1215 liquid chemicals and 14 predictors have been input to train the developed machine learning models via k-fold cross validation with the consideration of principal component analysis; The second TTP process safety study makes contributions on exploring inherently safer marine fuels by offering a liquid combustion risk criterion for ship compression ignition engines, two unsupervised machine learning clustering models were developed by considering liquid flammability flame propagation and aerosol formulation characteristics

Advances in Evolutionary Algorithms

With the recent trends towards massive data sets and significant computational power, combined with evolutionary algorithmic advances evolutionary computation is becoming much more relevant to practice. Aim of the book is to present recent improvements, innovative ideas and concepts in a part of a huge EA field