94 research outputs found
Dr. Yucel Yanikdag – Faculty Author Interview
No full textDr. Yucel Yanikdag, Associate Professor of History discusses his new book, Healing the Nation: Prisoners of War, Medicine and Nationalism in Turkey, 1914-1939, published recently by Edinburgh University Press. In this book, he explores how Ottoman prisoners of war and military doctors of the First World War discursively constructed their nation as a community, and at the same time attempted to exclude certain groups from that nation. Yanikdag aims to broaden the discussion of nationalism to explore how ideological and biological factors influenced each other
Characterization and comparison of mine wastes in Can Coal Basin, northwest Turkey: a case study
No full textThe Can Coal Basin is a major coal-producing site in northwest Turkey that has faced acid mine drainage problems since the 1980s. This study characterized and compared mine wastes from the Etili and Comakli open-pit coal mines in the Can Coal Basin physically, mineralogically, and geochemically for acid mine drainage potential and metal(loid) mobility. Mineralogical analysis determined pyrite to be the major sulfide mineral in the Etili and Comakli coal and mine wastes, while dolomite and calcite were abundant in the mine wastes from the Comakli site. Concentrations of Al, As, Mn, and Pb in these mine wastes are higher than in Turkish and world coals. The enrichment factor showed moderate enrichment of Pb and significant enrichment of As in the Etili and Comakli mine wastes, respectively. Static tests indicated acid generation potential in all Etili and some Comakli mine wastes. The modified synthetic precipitation leaching procedure revealed that greater concentrations of Al, Fe, Mn, Ni, Pb, and SO42- were released from pyrite-rich mine wastes. Physical, mineralogical, and geochemical factors affecting acid mine drainage were highly variable within and between sites. Increasing concern over significant environmental health effects of low-pH, metal(loid)-polluted mine wastes necessitates remediation of the mine sites.Scientific Research Projects Coordination Unit of Canakkale Onsekiz Mart University [FBA-2016-759]This research was partly supported by the Scientific Research Projects Coordination Unit of Canakkale Onsekiz Mart University under FBA-2016-759 numbered project. The author thanks to Canakkale Onsekiz Mart University Science and Technology Application and Research Center for SEM-EDX analysis. The author is grateful to Assoc. Prof. Mehmet Ali Yucel for his help during field studies, Dr. Burcu Ileri for her assistance in laboratory work and Dr. Mehmet Karadeniz for his constructive comments. Furthermore, the author special thanks to the four anonymous reviewers for their valuable suggestions
An experimental study on friction reducing polymers in turbulent pipe flow
No full textAn experimental study was conducted to search the reduction of friction in fully developed turbulent pipe flow using different types of polyacrylamides as friction reducing polymers. Pressure drop measurements determined the friction reduction. Three different polymer types Superfloc A110, Superfloc A130 and Superfloc A150 were used to examine the effect of polymer concentration, Reynolds number and polymer type on friction reduction. The Darcy friction factor was obtained for each polymer type at the polymer concentration ranging from 0 to 500 wppm and a Reynolds number range of 10000-80000. It was observed that friction factor decreased with increment in polymer concentration and Reynolds number for each polymer. Higher molecular weight polymers are more effective at reducing friction. With increasing concentration of polymer, the measured data approaches the Virk asymptote, which represents the maximum friction reduction limit by the polymers. The percentage of friction reduction increased with increasing concentration of polymer up to 100 wppm for each polymer type and then began to decrease for polymer concentrations higher than 100 wppm. An empirical formula was obtained to calculate the Darcy friction factor as a function of Reynolds number and polymer concentration for Superfloc A110.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Marine and Transport Technolog
Energy Transition in The Dutch Dwelling Stock: Exploring the Extent of Inertia Against Change
No full textThe residential sector accounts for 30% of the total energy consumed by all sectors on average worldwide. This significant share makes an energy transition in the residential sector one of the most important frontiers of sustainability transitions. Netherlands aims to achieve a remarkable reduction in the energy consumption in residential buildings with policies mainly aiming at new constructions, and little attention is being paid to the existing dwelling stock. However, the existing dwelling stock creates an inertia against a transition. Although this is a widely accepted issue, the extent of such an inertia has not been analyzed explicitly. In that respect, we aim to conduct a preliminary study in order to demonstrate the importance of the existing dwelling stock, and the inertia it can cause during an energy transition process. Besides, we also aim to explore effectives of certain policy options that can alleviate this inertia. For that purpose, a simulation model is developed and initialized based on the Dutch housing system. The set of experiments discussed in the paper provides a better understanding about this inertia, as well as what needs to be done for achieving significant progress in a residential energy transition.Multi Actor SystemsTechnology, Policy and Managemen
Artykuł oryginalnyBrucella endocarditis – a registry study
No full textBackground: A zoonotic infection caused by Brucella spp., brucellosis, is endemic in some areas of the world, like in our country. One of the most devastating conditions related to this infection is endocarditis, although it is rare. Unfortunately, adequate studies on the characteristics of Brucella endocarditis have not been performed. In addition, there was no consensus on optimal type and duration of medical and interventional therapies. Aim: To answer the following questions: what are the clinical characteristics of Brucella endocarditis, which type of therapy should be performed, and can an alternative antibiotic regimen be applied? Methods: Patients with the diagnosis of Brucella endocarditis were included in the study during a 6-year period. A total of 10 patients were interrogated for their signs, symptoms, drug use, and clinical conditions. In addition, baseline clinical and laboratory characteristics of the patients were evaluated. Results: All patients in the study were male with a mean age of 55.9 ± 12.7 years. Hospitalisation and total follow-up periods were 52.6 ± 11.2 and 80.6 ± 29.0 days, respectively. The most frequently presenting symptom was fever (60%). Dyspnoea and fatigue were the other frequent symptoms in descending order. Valve pathology was present in 70% of the study population. The aortic valve was affected more than the mitral valve. Affected mitral valves had rheumatic disease whereas only 57% of the aortic valves had underlying pathology. Isolation of Brucella spp. was possible in 20% of the patients. Mortality rate was 30% in our study; 20% of the patients were on medical follow-up without disease progression and with clinical stability, 60% of patients were on a combination therapy with a tetracycline group, a rifampicin, and a third-generation cephalosporin. Patients who took this combination and underwent aortic valve replacement had good clinical results with a mortality rate of 20%. The 30% of patients were on a combination therapy with a tetracycline group, rifampicin, and an aminoglycoside group. Mortality rate with this combination was 33%, although the success rate was 67%. Conclusion: Brucella endocarditis should be considered in the differential diagnosis in patients with vegetations on the cardiac valves, especially in endemic areas. Optimal therapy seems to be a combination of antibiotics and surgery, although medical therapy can be an alternative, especially in stable patients. Addition of a third-generation cephalosporin instead of aminoglycoside to the combination therapy is an alternative.Wstęp: Bruceloza występuje w różnych endemicznych rejonach świata, w tym w Turcji. Jednym z najcięższych, ale sporadycznie spotykanych powikłań brucelozy jest infekcyjne zapalenie wsierdzia (IZW). W piśmiennictwie nie ma badań opisujących w pełni to powikłanie brucelozy. Cel: Przedstawienie klinicznego obrazu IZW wywołanego brucelozą, ocena skuteczności leczenia, w tym możliwości zastosowania niestandardowej antybiotykoterapii. Metody: W ciągu 6 lat chorzy z IZW wywołanym brucelozą włączani byli do specjalnego rejestru. W sumie grupa badana składała się z 10 chorych, u których poddano analizie wszystkie dostępne dane kliniczne i laboratoryjne. Wyniki: Wszyscy chorzy byli płci męskiej, a ich średni wiek wynosił 55,9 ± 12,7 roku. Czas hospitalizacji i obserwacji ambulatoryjnej wynosił odpowiednio 52,6 ± 11,2 i 80,6 ± 29,0 dni. Najczęściej spotykanym objawem przy przyjęciu była gorączka – 60% chorych, a następnie duszność i męczliwość. Wady zastawkowe wykryto u 70% chorych. Zastawka aortalna zajęta była procesem chorobowym częściej niż zastawka mitralna. Proces reumatyczny dotyczył wszystkich zajętych zastawek mitralnych i 57% zastawek aortalnych. Izolacja drobnoustroju Brucella spp. możliwa była u 20% chorych. Śmiertelność wyniosła 30%. U 20% chorych stosowano leczenie farmakologiczne, uzyskując stabilizację choroby. U 60% chorych stosowano złożoną antybiotykoterapię, w skład której wchodziły tetracykliny, ryfampicyna i cefalosporyna trzeciej generacji. Chorzy leczeni takim zestawem antybiotyków, u których następnie wymieniono zastawkę aortalną, rokowali względnie dobrze, a śmiertelność wynosiła 20%. U 30% chorych stosowano tertracykliny, ryfampicynę i aminoglikozyd – w tej grupie śmiertelność wyniosła 33%. Wnioski: Infekcyjne zapalenie wsierdzia spowodowane brucelozą powinno być zawsze brane pod uwagę, jeśli stwierdza się wegetacje na zastawkach serca, szczególnie u osób pochodzących z rejonów endemicznych. Optymalnym postępowaniem wydaje się połączenie antybiotykoterapii i wymiany zastawki, aczkolwiek samo leczenie farmakologiczne może być skuteczne, szczególnie u chorych w stanie stabilnym. Ponadto wydaje się, że korzystne może być zastosowanie cefalosporyn trzeciej generacji zamiast aminoglikozydów
Communicating model insights using interactive learning environments
No full textMuch attention is focused on the rational and advisory style of developing and applying System Dynamics models. Even group model building focuses primarily on the formulation and understanding of the model by the group members themselves. There is a dearth of attention for communication of the insights derived during the model building process to those peripherally or (un)involved in this process. In this study, the multi-actor context of model implementation is addressed explicitly. The feedback loop connecting model-derived insights and results back to the problem owners, the client and stakeholders, is explored. A number of principles for use in the communication of models are derived and the rôle of interactive learning environments as a tool in communicating model insights in such a multi-actor context is discussed.Multi Actor SystemsTechnology, Policy and Managemen
Investigating an automated method for the sensitivity analysis of functions
No full textAutomated sensitivity analysis approaches in system dynamics focus primarily on model parameters. Although table functions are often subjectively approximated, they do not form the focus of most sensitivity analyses. Recently, a promising approach that allows automation of sensitivity analysis on functions was proposed by Hearne (2010), but the applicability of this method to system dynamics table functions has not been studied, yet. In this study, the new method is applied to a simple system dynamics model. In the light of the observations a number of shortcomings are identified and a set of extensions to address these are proposed and then tested. The results of experiments with the original and the extended method demonstrate that the method can be used easily and efficiently for table functions. The extensions are shown to be valuable in creating a more comprehensive method, but they also raise the research issue of the tradeoff between their added value and the cost of dealing with increased complication. Apart from our experimental results, the article also puts forth a set of directions along which the approach can be improved further. Despite the issues requiring further research, the method holds promise for routine implementation.Multi Actor SystemsTechnology, Policy and Managemen
Development of independent MU/treatment time verification algorithm for non-IMRT treatment planning: A clinical experience
No full textEnergy Transitions towards Sustainability I: A Staged Exploration of Complexity and Deep Uncertainty
No full textThis paper illustrates the use of Exploratory System Dynamics Modeling and Analysis – a multi-method combining System Dynamics and Exploratory Modeling and Analysis to explore and analyze uncertain dynamic issues and test deep policy robustness. This paper gives an overview of the current state of this multi-method by means of an illustration. The multimethod is applied to the transition of the electricity generation system, more specifically the battle between old and new electricity generation technologies. Starting from a small System Dynamics model about the battle, uncertainties are added to turn it into an exploratory variant which is used as a scenario generator in the multi-method. In a follow-up paper, model and method uncertainties are added and explored by joint consideration of the exploratory model, another (large) System Dynamics model, and an Agent Based model. By reading both papers, the reader is taken step by step from the identification of uncertainties, development of System Dynamics models, transformation of these models into exploratory models by adding uncertainty-related structures and formulations, to the stage-wise exploration of different types of uncertainties – starting with parameter uncertainties, subsequently adding uncertainties related to functions, structures, models, and methods.Multi Actor SystemsTechnology, Policy and Managemen
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