Most materials used in many industries such as plastic, food, pharmaceuticals, electronics, dye, etc. exhibit viscoelastic properties under their processing or flow conditions. Due to the elasticity of such materials, deformation-stress in addition to their hydrodynamic behavior differ from simple Newtonian fluids in many important respects. Rod climbing, siphoning, secondary flows are all common examples to how a viscoelastic fluid can exhibit quite distinctive flow behavior than a Newtonian fluid would do under similar flow conditions. In industrial processes involving flow of viscoelastic materials, understanding complexities associated with the viscoelasticity can lead to both design and development of hydrodynamically efficient processes and to improved quality of the final products. In the present study, the main objective is to develop two dimensional finite volume based convergent numerical algorithm for the simulation of viscoelastic flows using nonlinear differential constitutive equations. The constitutive models adopted are Oldroyd-B, Phan-Thien Tanner (PTT) and White-Metzner models. The semi-implicit method for the pressure-linked equation (SIMPLE) and SIMPLE consistent (SIMPLEC) are used to solve the coupled continuity, momentum and constitutive equations. Extra stress terms in momentum equations are solved by decoupled strategy. The schemes to approximate the convection terms in the momentum equations adopted are first order upwind, hybrid, power-law second order central differences and finally third order quadratic upstream interpolation for convective kinematics QUICK schemes. Upwind and QUICK schemes are used in the constitutive equations for the stresses. Non-uniform collocated grid system is employed to discretize flow geometries. As test cases, three problems are considered: flow in entrance of planar channel, stick-slip and lid driven cavity flow. Detailed investigation of the flow field is carried out in terms of velocity and stress fields. It is found that range of convergence of numerical solutions is very sensitive to the type of rheological model, Reynolds number and polymer contribution of viscosity as well as mesh refinement. Use of White-Metzner constitutive differential model gives smooth, non oscillatory solutions to much higher Weissenberg number than Oldroyd-B and PTT models. Differences between the behavior of Newtonian and viscoelastic fluids for lid-driven cavity, such as the normal stress effects and secondary eddy formations, are highlighted. In addition to the viscoelastic flow simulations, steady incompressible Newtonian flow of lid-driven cavity flow at high Reynolds numbers is also solved by finite volume approach. Effect of the solution procedure of pressure correction equation cycles, which is called inner loop, on the solution is discussesed in detail and results are compared with the available data in literature.

A conceptual site model (CSM) is simply a description of the environmental conditions at a contaminated site and surrounding area, which provides all interested parties with a vision of the site. CSM mainly identifies the source-pathway&amp / #8208 / receptor linkage to guide for effective site characterization, risk assessment and remedial investigations. Development of CSM is complicated because it is &lsquo / case specific&rsquo / and there is no single route to follow during decision making concerning the contaminated site. Moreover, type and extent of information needed varies according to size and level of contamination and site heterogeneity. The objective of this study is to develop a decision support tool that guides the site assessors during identification of possible decision routes that can be encountered / the procedure to be followed / and the information and data to be collected at each stage. This tool also introduces interactions between CSM andsampling strategies designed for various purposes. Developed decision support tool adapts to each specific contaminated site. Furthermore, a detailed review of sampling strategies is presented as a guidance for site assessors. The decision support tool is equipped with standardized tools used for CSM development, i.e. information/data collection forms, illustrative tools and exposure pathway diagram. Information on site, geology, hydrogeology, contamination source, contaminants and receptors is collected via CSM form. Illustrative tools may vary from very simple site sketches to very complex 3D drawings depending on the needs of the specific contamination cases. Exposure pathway diagram (EPD) is used to identify all transport mechanisms and potential exposure pathways. EPD is embedded into a user&amp / #8208 / friendly decision assistance tool based on Microsoft Excel and Visual Basic for Applications. The applicability and utility of the decision support tool was tested using two case studies. Case study applications indicated that the developed methodology satisfies the objectives aimed in this study.

Evaluation of contaminated sites based on human health and environmental hazards is an essential task for the proper management of the contaminated sites. A large number of contaminated sites have been waiting for remediation all over the World. However, contaminated site remediation is generally a difficult, time consuming and very expensive process. Ranking systems for contaminated sites are useful tools to determine the remedial priority and to manage the available remediation budget in the most efficient way before the costly remedial actions are taken. To be able to have a reliable ranking result, accurate and sufficient amount of data on the nature of contamination and site characteristics are needed, which are usually not available at the early identification phases of contaminated sites, and the available data is mostly limited and vague in nature. If the available data are inaccurate or vague, the corresponding remedial ranking results can be questionable, as well. Most of the current ranking methodologies overlook the vagueness in the parameter values. The main objective of this study is to develop a remedial priority ranking system for contaminated sites by taking vagueness in parameter values into account. Within this context, development of the new Remedial Priority Ranking System, RPRS, aims to define and evaluate the current and possible environmental risks by using sufficiently comprehensive readily available parameters describing the fate and transport of contaminants in the environment and considering vagueness in those parameter values. The consideration of vagueness in parameter values was included in remedial prioritization of contaminated sites by means of fuzzy set theory. A fuzzy expert system was built up for the evaluation of contaminated sites and it was developed in Microsoft Office Excel 2007 platform, with the intention of making the evaluation fast and user friendly. Hypothetical and real case study applications are presented to test ease of use and validity of the results of the developed methodology. Results of case study applications revealed that the developed RPRS can serve as an alternative method for remedial priority ranking of contaminated sites.

ABSTRACT DEVELOPMENT OF A COMPUTER PROGRAM FOR FRICTION WINDING SYSTEM DESIGN &Uuml / nal, Fuat G&ouml / khan M.Sc., Department of Mining Engineering Supervisor: Prof. Dr. Naci B&ouml / l&uuml / kbasi September 2011, 99 pages As the trend to deeper mines continues, mine hoists and associated equipment will become more sophisticated, complex, large and expensive. Correct selection of the right type of hoist is imperative. In this vital link between underground and surface, crude estimates of hoist capacity are not good enough, and the mining engineer must design and select the right hoisting system to meet the design specifications and establish the most suitable operating parameters. This study aims to constitute a software model, which results all required design parameters of friction type winding system on minimum required power. The computer program has been structured on Microsoft Visual Basic programming language. The program requires user inputs (winding depth, hourly hoisting capacity) and selections (type and number of motors, type of friction wheel mounting) to run macros and equations so that the operating parameters such as skip capacity, rope type and diameter, hoisting speed, acceleration, cycle period, friction wheel diameter are determined to give the minimum motor power requirement.

Aprotic solvents are organic solvents which do not easily react with a substance dissolved in it and they do not exchange protons despite of their high ion and polar group dissolving power. Therefore, this characteristic property makes aprotic solvents very suitable intermediates in many industries producing pharmaceuticals, textile auxiliaries, plasticizers, stabilizers, adhesives and ink. Dehydration of these mixtures and recirculation of valuable materials are substantial issues in industrial applications. The conventional method for recovery of aprotic solvents has been distillation, which requires excessive amount of energy to achieve desired recovery. Hydrophilic pervaporation, which is a membrane based dehydration method with low energy consumption, may become an alternative. Because of high dissolving power of aprotic solvents only inorganic membranes can be employed for this application. In this study three types of inorganic membranes (NaA zeolite, optimized silica and HybSi) were employed. Main objective of this studys to investigate effect of membrane type and various operationg parameters (feed composition at a range of 50-5% and temperature at a range of 50-100oC) on pervaporative dehydration of aprotic solvents / dimethylacetamide, dimethylformamide and n-methylpyrrolidone. During the experiments, feed samples were analyzed with Karl Fischer Titration Method / permeate samples were analyzed with Gas Chromatography. Experiments showed that proper dehydration of aqueous aprotic solvent mixtures was succeded with all three membranes investigated. In the target feed water content range (50 to 20%wt), permeate water contents were higher than 98%wt which was quite acceptable for all membranes. Moreover, NaA zeolite membrane performed higher fluxes than optimized silica and HybSi in composition range of 50 to 15% water at 50oC. It was also observed that HybSi membrane had higher fluxes and permeate water contents than optimized silica membrane for all solvents. On the other hand, the rates of decrease in permeate fluxes changed depending on the type of solvent for optimized silica and HybSi membranes. With both membranes, permeate flux of dimethylformamide decreased much slower than that of n-methylpyyrolidone. Furthermore, the results showed that permeate fluxes of HybSi membrane increased with increasing operation temperature due to the change of solvent activity in mixture. In addition, an Arrhenious type equation was used to describe changes in fluxes with changing temperature. It was also found that activation energy of water for diffusion through HybSi membrane was calculated as 8980 cal/mol.

Chemical composition of particles and rain water at three sites in Turkey were extensively compared to determine if there is a relationship between aerosol and rain composition. If such relationship exists, it can allow one to construct rain water composition using aerosol data. This is important because, rain composition data is scarce as sampling and analysis of very low concentrations of elements and ions in rain water is more difficult compared to sampling and analysis of atmospheric aerosol. Results showed that aerosol composition can be closely reflected in composition of rain water if below cloud processes dominate over the incloud processes. This is clearly observed for crustal elements in all stations and for most of the elements in urban Ankara station. However, in rural stations there were differences in rain and aerosol that is attributed to significant contribution from in cloud processes. Seasonal patterns and enrichment factors observed in aerosol composition showed general agreement with corresponding temporal variations observed in rain water concentrations of elements, but short term variations became visible only if data is averaged over a long period of time. These observations suggest that certain features of rain water composition can be constructed from if concentration data is available for aerosols. However it should be noted that there are also significant differences between stations and between elements or element groups, indicating that composition of rain water constructed from aerosol data can only be a crude one. Similarities between rain and aerosol compositions is more pronounced in urban Ankara station compared to rural stations used in this study. Factor analysis performed to aerosol and rain water data sets showed that source types affecting chemical composition of rain and particles are generally the same, bur contribution of each source type to rain and aerosol composition shows differences. Similarly, the source regions, defined by potential source contribution function, affecting aerosol and rain compositions are not identical. In Antalya station Source regions affecting chemical composition of rain water are more local compared to source regions affecting composition of aerosol. Same difference is not observed in Amasra station. Scavenging ratios is found to be a suitable tool to construct rain water composition using aerosol data. Scavenging ratios calculated using paired daily data are more variable both between stations and within a station. Long-term averaged data was found to be more reliable for calculating SRs of elements and ions at all stations.

Στην παρούσα εργασία με τη χρήση της Περιβάλλουσας Ανάλυσης Δεδομένων (Data Envelopment Analysis, DEA) υπολογίζεται η αποτελεσματικότητα των πολιτικών υγείας διαχρονικά, για κάθε έτος της τριετία 2008-2010 με τη χρήση της Window Analysis, στις χώρες που είναι ενταγμένες στον Οργανισμό Οικονομικής Συνεργασίας και Ανάπτυξης (ΟΟΣΑ). Επίσης, δημιουργούνται πρότυπα για το πώς μπορούν να βελτιωθούν οι μη αποτελεσματικές χώρες. / Στην παρούσα εργασία με τη χρήση της Περιβάλλουσας Ανάλυσης Δεδομένων (Data Envelopment Analysis, DEA) υπολογίζεται η αποτελεσματικότητα των πολιτικών υγείας διαχρονικά, για κάθε έτος της τριετία 2008-2010 με τη χρήση της Window Analysis, στις χώρες που είναι ενταγμένες στον Οργανισμό Οικονομικής Συνεργασίας και Ανάπτυξης (ΟΟΣΑ). Επίσης, δημιουργούνται πρότυπα για το πώς μπορούν να βελτιωθούν οι μη αποτελεσματικές χώρες.

In this study, flue gas emissions and combustion efficiencies during combustion and co-combustion of olive cake and coal are investigated in a bubbling fluidized bed with an inside diameter of 102 mm and a height of 900 mm and 1900 mm. Tun&ccedil / bilek lignite coal and Edremit olive cake were used in the experiments as fuels. Temperature distributions along the combustion column were continuously measured. Flue gas concentrations of O2, CO, SO2 and NOx were measured during combustion experiments. Four sets of experiments were performed in order to examine the effect of fuel composition, excess air ratio, freeboard extension and limestone addition on flue gas emissions and combustion efficiency. The olive cake addition to coal were 25, 50, 75 % by wt. The bed temperature on the average was 850 oC. The results of the experiments showed that coal combustion occurs at lower parts of the combustion column whereas olive cake combustion takes place more in the freeboard region. As olive cake percentage in the fuel mixture increased, CO emissions increased, SO2 and NOx emissions decreased. The reason for the decrease of NOx emissions with increasing percentage of olive cake in the fuel mixture was due to a reducing atmosphere created in the combustion column. Mostly combustion losses resulted mainly from the unburnt carbon in the fly ash. With the freeboard extension, noticeable decrease in CO emissions and slight increase in combustion efficiencies were observed. Among the limestones tested, &Ccedil / an limestone gave the best result with Ca/S = 3 at an optimum bed temperature of 850 oC. The SO2 reduction was 87% at this Ca/S ratio. For co-combustion experiments, it was observed that SO2 adsorption efficiency of limestone increased with the addition of olive cake to the fuel mixture.

The present study presents a draft national CCT (Clean Coal Technologies) and CCS (Carbon Capture and Storage) technology roadmap to policy makers. Various technical and non-technical (economic and social) challenges that currently prevent CCT and CCS from being a widely used commercial technology are discussed and the goals for each research pathway are defined. The process of creating the roadmap started with a review and assessment of the existing national and international technology roadmaps which represent a global picture of the state of the art and national and international plans for future on CCT and CCS research development, demonstration and deployment (R&amp / D&amp / D). Following this step, the national situation, capacities and priorities were examined. Finally, R&amp / D&amp / D actions discussed in the existing roadmaps and/or new actions were carefully selected and suggested as a draft Turkish CCT and CCS Roadmap that needs further development and discussion by the input of interdisciplinary national stakeholders. As a conclusion a number of technical and non-technical suggestions are delivered.

Tsunamis are characterized as shallow water waves, with long periods and wavelengths. They occur by a sudden water volume displacement. Earthquake is one of the main reasons of a tsunami development. Historical data for an observation period of 3500 years starting from 1500 B.C. indicates that approximately 100 tsunamis occurred in the seas neighboring Turkey. Historical earthquake and tsunami data were collected and used to develop two artificial neural network models to forecast tsunami characteristics for future occurrences and to estimate the tsunami return period. Artificial Neural Network (ANN) is a system simulating the human brain learning and thinking behavior by experiencing measured or observed data. A set of artificial neural network is used to estimate the future earthquakes that may create a tsunami and their magnitudes. A second set is designed for the estimation of tsunami inundation with relation with the tsunami intensity, the earthquake depth and the earthquake magnitude that are predicted by the first set of neural networks. In the case study, Marmara and Aegean regions are taken into consideration for the estimation process. Return periods including the last occurred earthquake in the Turkish seas, which was the izmit (Kocaeli) Earthquake in 1999, were utilized together with the average earthquake depths calculated for Marmara and Aegean regions for the prediction of the earthquake magnitude that may create a tsunami in the stated regions for various return periods of 1-100 years starting from the year of 2004. The obtained earthquake magnitudes were used together with tsunami intensities and earthquake depth to forecast tsunami wave height at the coast. It is concluded that, Neural Networks predictions were a satisfactory first step to implement earthquake parameters such as depth and magnitude, for the average tsunami height on the shore calculations.