Identification and Screening of Biomarkers of Human Exposure to Environmental and Food Toxicants in Sewage

Pesticides are active substances with potentially adverse effects on human health, and therefore great effort is addressed to study the relation between their widespread use and human exposure. Human biomonitoring (HBM) is the most widely used and powerful tool to evaluate the exposure of the population to these substances. However, novel approaches are needed in order to give additional information on exposure at population level and overcome the limitations of HBM studies. A novel approach, called Wastewater-Based Epidemiology (WBE), was proposed as an alternative “biomonitoring tool” with the aim to assess the population exposure to organophosphates, triazines and pyrethroids. A specific analytical method based on liquid chromatography tandem mass spectrometry was developed and validated to measure human urinary metabolites of pesticides in influent wastewater. This method was applied to samples collected from wastewater treatment plants of fifteen European cities. Pyrethroids metabolites were suitable to back-calculate human exposure to this class. Generally, the results obtained from wastewater were in agreement with the urinary biomarker levels of HBM studies, taking into account the dilution of urine in wastewater. Spatial differences were observed on pesticide exposure in Italy and Europe and seasonal variations in human intake of pyrethroids were found, as expected, with higher intakes during spring/summer. Mass loads profiles of pesticides metabolites in the different European cities were in accordance with the use reported in the Eurostat official statistics. This novel WBE method can be used for obtaining objective and updated, direct information on the real levels of pesticide exposure in the general population, and can complement the findings of HBM studies. The method can also provide valuable information for public health organizations, such as the United States Environmental Protection Agency, the World Health Organization and the Centers for Disease Control and Prevention

The Truth is Out There: The Use of Conspiracy Theories by Radical Violent Extremist Organizations

This paper sought to examine conspiracy theory (CT) use across three types of groups: radical violent extremists (RVE), non-violent extremists, and moderates. Using the theory of significance quest, or the desire for one’s life to have meaning (Kruglanski, Chen, Dechesne, Fishman, & Orehek, 2009), I sought to determine whether RVE groups were more likely to use CTs, invoke need for cognitive closure (NFCC) via the use of time pressure, elicit anomie, and promote significance quest through violence than the other groups. Using text analysis software, I pulled passages from six groups – two from each level of extremism - that had conspiratorial language and then coded for the variables described above. RVE groups were significantly more likely than the other groups to use CTs and invoke NFCC through time pressure but were less likely than non-violent groups to elicit anomie. In addition, RVE groups were more likely to promote significance gain through action, but not significance restoration or prevention of significance loss. Implications of the findings are discussed

Optimal design and operation of hybrid AC/DC microgrids towards more resilient energy systems

Humanity has recently embarked on an ambitious journey to decarbonise the world in an effort to reverse the adverse effects of the practices deployed the past two centuries, which have led us to a serious climate change. Regulation and policy have been introduced by countries worldwide to encourage, promote and compensate these efforts, including the UK’s recent announcement pledging to be the first major economy eliminating their contribution to carbon emissions. A comprehensive framework for coordinating actions to reduce CO2 emissions is expected to be put forward addressing the challenges arising, including a significant transformation of the energy system, a restructuring of the energy market and a new way of engaging with the wider public to making what is conceptually significant, perceptually prominent. Within this context, the concepts of smart grids and, in a smaller scale, microgrids have arisen to assist these decarbonisation efforts. Microgrids have a great potential to actively contribute to grid health status, however the current practices in network design and operation hinder the capabilities of these types of networks. In fact, they do not allow microgrids to realise their potential and enable a paradigm shift in delivering resilience and security of supply from redundancy in network assets and preventive control to a more intelligent operation at the distribution level through corrective control actions. This thesis proposes innovative design and operational models for microgrids, and particularly hybrid AC/DC microgrids, that optimise the total system cost while satisfying pre-specified resilience targets. The modelling framework introduced comprises of a tailor-made genetic algorithm (i.e. for optimal sizing) combined with a detailed AC optimal power flow (OPF) that captures the technical characteristics of both the AC and DC subgrids with an extensive set of technologies considered. The proposed approach, being able to capture technical characteristics such as voltage and frequency through a detailed power flow algorithm, provides accurate solutions and therefore can meaningfully address operational challenges of microgrids. Its capability to additionally capture contingencies ensures that the proposed sizing solutions are suitable both during normal operation and transient states. Finally, the genetic algorithm provides convergence of the model with relative computational simplicity, which is why it has been particularly developed for the needs of this thesis. An innovative Dynamic Stability Constrained OPF is proposed as an extension that incorporates differential equations, such as the swing equation, characterising the operation of power systems. This is achieved via appropriate conversion of the equations to numerically-equivalent algebraic equations. This novel aspect will enable optimal decisions to be taken considering stability properties, which are undeniably necessary in the context of energy systems with renewable penetration of above 50% and are proven to significantly impact the system cost. Resilience is also central to this thesis, hence it is discussed and limitations of current research typically confusing resilience with reliability are identified. Subsequently, a definition to help the industry merge towards a common understanding and a way of quantifying resilience (particularly relevant to microgrids) are proposed. As a last step, this thesis identifies the imminent digitalisation energy systems are undergoing and utilising its merits, it introduces a strategy for interaction between distribution networks (incorporating microgrids as one type of resource) and transmission systems with the focus being on exchange of voltage support services. The operational models developed in this thesis could prove to be useful towards optimising the portfolio of assets to provide the services required.Open Acces

Effects of a School-Wide Behavior Intervention Plan on a Rural Middle School

The purpose of this study was to collect office referral data from seventh grade students at a rural middle school in order to assess the effectiveness of a school-wide Positive Behavior Support System (PBS). Pre and post implementation data was collected and evaluated. The results of the paired samples t-test were mixed and allowed for multiple interpretations. The raw data showed that office referrals actually went up for the second half of the year once the PBS was put into action. The causation for this increase is discussed

Μελέτη μικροδομής-μηχανικών ιδιοτήτων σε υπερωστενιτικούς χάλυβα συγκολλημένους με τεχνικές EBW/TIG

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Επιστήμη και Τεχνολογία Υλικών

Disciplined Exploitation of Emergent Properties

Digital systems are becoming increasingly complex, requiring significantly more effort and resources in order to be designed, implemented, and maintained. In the last decade, industry and academia alike share the concern that in the near future engineers will have to face unprecedented levels of complexity. Similarly, the belief that traditional engineering approaches will be insufficient for coping with systems of such complexity is gaining increasingly more supporters. An alternative approach suggests the use of implicit engineering techniques which could lead to complex global-level behaviours by focusing solely on the local, or individual, level. The quality of rising macroscopic behaviours which are irreducible, or non-trivial to reduce, to any microscopic properties is more widely known as emergence, especially in the fields of complex and multi-agent systems. This work aims to investigate the possibility of engineering systems which harness, in intentional and disciplined ways, beneficial emergent properties. An experimental framework is being proposed to assist system designers towards that goal. This framework is based on the results and experience gained by Paunovski during the design of the Emergent Distributed Bio-Organisation (EDBO) case study. EDBO has demonstrated a number of beneficial emergent properties rising out of simple, bio-inspired, local interactions. The original implementation of the EDBO case study is closely coupled with a custom simulation platform; both developed by the same author. This work provides a basis for separating the EDBO case study from this combined implementation, by documenting it concisely and defining it in a formal manner. This formal model allows for rigorous testing and enables other authors to reuse the EDBO principles in their systems. The model is validated informally through animation and it serves as the basis of an independent implementation which cross-validated many of EDBO's original findings

DC voltage control for fault management in HVDC system

This paper focuses on the transmission system options for connection of offshore wind farms and investigates the advantages and disadvantages of proposed concepts in order to draw a conclusion regarding their suitability for connection in the electricity system. Then, the most appropriate solution is implemented in Matlab/Simulink to show its benefits. For this purpose, 5 wind farms are connected to an offshore station and their power output is transferred onshore via a point – to – point DC link. Additionally a novel proposal of DC voltage control is included in the model to simulate the behaviour of the system when faults occur in the electricity grid

Enhanced DC voltage control strategy for fault management of a VSC-HVDC connected offshore wind farm

This paper proposes a DC voltage control strategy for fault management taking into advantage the operation of the master controller located in the offshore AC substation platform. The issue resolved via the proposed controller relates to over-voltages caused in the HVDC links when the power transfer onshore is disrupted due to faults occurring at the AC side of the onshore grid. The control strategy presented in this paper proposes an effective way of maintaining the DC over-voltage within safety limits via reducing the connected wind farm power output. The operation of the aforementioned control strategy requires small computational power and no communication