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Article Citation - WoS: 29Citation - Scopus: 38An Experimental Study of Cutting Performances of Worn Picks(Springer Wien, 2016) Dogruoz, Cihan; Bolukbasi, Naci; Rostami, Jamal; Acar, CemilThe best means to assess rock cuttability and efficiency of cutting process for using mechanical excavation is specific energy (SE), measured in full-scale rock cutting test. This is especially true for the application of roadheaders, often fitted with drag-type cutting tools. Radial picks or drag bits are changed during the operation as they reach a certain amount of wear and become blunt. In this study, full-scale cutting tests in different sedimentary rock types with bits having various degree of wear were used to evaluate the influence of bit wear on cutting forces and specific energy. The relationship between the amount of wear as represented by the size of the wear flats at the tip of the bit, and cutting forces as well as specific energy was examined. The influence of various rock properties such as mineral content, uniaxial compressive strength, tensile strength, indentation index, shore hardness, Schmidt hammer hardness, and density with required SE of cutting using different levels of tool wear was also studied. The preliminary analysis of the data shows that the mean cutting forces increase 2-3 times and SE by 4-5 times when cutting with 4 mm wear flat as compared to cutting with new or sharp wedge shape bits. The grain size distribution of the muck for cutting different rock types and different level of bit wear was analyzed and discussed. The best fit prediction models for SE based on statistical analysis of laboratory test results are introduced. The model can be used for estimating the performance of mechanical excavators using radial tools, especially roadheaders, continuous miners and longwall drum shearers.Article Citation - WoS: 24Citation - Scopus: 30Dynamic Assessment of Multi-State Systems Using Phase-Type Modeling(Elsevier Sci Ltd, 2015) Eryilmaz, SerkanMulti-state systems have attracted great attention due to their wide applications in engineering. They have been effectively used in modeling various systems such as power supply systems and transportation systems. In this paper, phase type modeling is proposed for dynamic assessment of nonrepairable multi-state systems when the system degrades According to a Markov process. The utility of phase type modeling is demonstrated in the computation of mean lifetimes, mean residual lifetimes, and derivation of survival functions of series and parallel systems. A stochastic comparison result between two systems is also obtained using phase representations of survival functions. Extensive numerical results are presented to illustrate the applicability of the approach. (C) 2015 Elsevier Ltd. All rights reserved.Book Part Citation - WoS: 61Citation - Scopus: 66Use of Waste Bread To Produce Fermentation Products(Elsevier Academic Press inc, 2013) Melikoglu, Mehmet; Webb, Colin[No Abstract Available]Conference Object A Solution To the Adhesion Problem of Oxide Thin Films on Zinc Selenide Optical Substrates(Soc Vacuum Coaters, 2016) Cosar, M. B.; Aydogdu, G. H.; Batman, H.; Ozhan, A. E. S.Zinc selenide optical substrates have high transparency within the 0.5- to 14.0-mu m wavelength range. This makes them an attractive candidate for multiband imaging applications in optical components. In order to minimize reflection loss in visible, near-infrared, and mid-infrared applications, zinc selenide lenses are coated with multi-layered oxide thin films by physical vapor deposition method or ion beam deposition. In this study, a four-layer anti-reflective filter at 1.064 gm and between 3.6 and 4.9 gm is applied to zinc selenide using an ion beam deposition system. The filter is used for a dual-beam optical application. The filter is composed of metal oxide layers that have an adhesion problem on zinc selenide. In order to solve this adhesion problem they were heat-treated at 300 degrees C for varying amounts of time prior to metal oxide coating. Treated samples were characterized in terms of their roughness, contact angle, morphology, refractive index, transparency, crystallography and chemical composition. Results show that it is possible to manufacture durable oxide thin film coatings on zinc selenide, by using a well-designed pre-treatment processes.Article Citation - WoS: 20Citation - Scopus: 20Properties of the Pc(4312) pentaquark and its bottom partner(Iop Publishing Ltd, 2021) Azizi, K.; Sarac, Y.; Sundu, H.We present an analysis of the newly observed pentaquark P-c(4312)(+) to shed light on its quantum numbers. To do that, the QCD sum rules approach is used. The measured mass of this particle is close to the Sigma D-++(c)- threshold and has a small width, which supports the possibility of its being a molecular state. We consider an interpolating current in a molecular form and analyze both the positive and negative parity states with spin-. We also consider the bottom counterpart of the state with similar molecular form. Our mass result for the charm pentaquark state supports that the quantum numbers of the observed state are consistent with J(P) = 1/2(-).Article Citation - WoS: 4Citation - Scopus: 4An Integrated Economy-Demography Model Reframed in a System Dynamics Setting(Wiley, 2019) Dural-Selcuk, Gozdem; Tunc, Huseyin; Tarim, S. ArmaganIn recent history, there has been an increasing concern about population aging and the associated increased economic burden in terms of high health-care expenses and pension payments. The need for decision support tools that can explore population dynamics has become a prominent issue. This study presents a comprehensive framework where one can scrutinize the key demographic drives of fertility (Total Fertility Rate/Age-Specific Fertility Rate) over macroeconomic indicators (technology, education, human capital) under exogenous mortality. The integrated model in this article is developed based on a reformulation of the unified growth theory. In the reformulated model, namely the "economy-demography model," the population age/sex structure is preserved, age-specific mortality is included, and fertility is measured in conventional demographic terms. The model is then presented in system dynamics framework, and its practical use is showcased with data obtained from the Turkish Statistical Institute. Copyright (c) 2020 System Dynamics SocietyConference Object Citation - Scopus: 50Internet-Of Smart Transportation Systems for Safer Roads(Institute of Electrical and Electronics Engineers Inc., 2020) Derawi,M.; Dalveren,Y.; Cheikh,F.A.From the beginning of civilizations, transportation has been one of the most important requirements for humans. Over the years, it has been evolved to modern transportation systems such as road, train, and air transportation. With the development of technology, intelligent transportation systems have been enriched with Information and Communications Technology (ICT). Nowadays, smart city concept that integrates ICT and Internet-of-Things (IoT) have been appeared to optimize the efficiency of city operations and services. Recently, several IoT-based smart applications for smart cities have been developed. Among these applications, smart services for transportation are highly required to ease the issues especially regarding to road safety. In this context, this study presents a literature review that elaborates the existing IoT-based smart transportation systems especially in terms of road safety. In this way, the current state of IoT-based smart transportation systems for safer roads are provided. Then, the current research efforts undertaken by the authors to provide an IoT-based safe smart traffic system are briefly introduced. It is emphasized that road safety can be improved using Vehicle-to-Infrastructure (V2I) communication technologies via the cloud (Infrastructure-to-Cloud - I2C). Therefore, it is believed that this study offers useful information to researchers for developing safer roads in smart cities. © 2020 IEEE.Article Citation - WoS: 11Citation - Scopus: 16Overcoming Environmental Challenges by Antagonizing Environmental Protesters: the Turkish Government Discourse Against Anti-Hydroelectric Power Plants Movements(Routledge Journals, Taylor & Francis Ltd, 2014) Ozen, HayriyeDue to the growing public importance of environmental concerns in the contemporary world, governments that prioritize economic interests over environmental concerns may try to counter environmental challenges not by openly declaring that they do not want to consider environmental demands, but by attempting to antagonize the protesters who voice such demands. This essay explores such a governmental response by analyzing the discourse articulated by the Turkish Government against movements that oppose the construction of hydroelectric power plants (HEPPs) on environmental grounds. In particular, the analysis focuses on how HEPPs, environmental claims and demands of movements, and environmental protesters are represented within the pro-HEPP discourse, and in what ways these representations appeal to popular perceptions. It is demonstrated that the discourse of the government attempts to counter the challenges of protesters by establishing an antagonist relation between the protesters and society by representing HEPPs as crucial for the economic development and, therefore, as compatible with the interests of society as a whole. Moreover, it also attempts to achieve this through portraying the protesters as criminals and terrorists who block the economic development of the country and pose significant threats to the commonwealth, not for legitimate environmental concerns but for some dubious motives and incentives. It is concluded that, with this approach, the government has managed to gain popular consent not only for the construction of HEPPs, but also for the repression of such movements.Article Citation - WoS: 32Citation - Scopus: 32Capacitance, Conductance, and Dielectric Characteristics of Al/Tio2< Diode(Springer, 2021) Gullu, H. H.; Yildiz, D. E.In this study, electrical properties of the Al/TiO2/p-Si diode structure with an atomic layer deposited TiO2 interface layer are investigated by current-voltage (I-V), capacitance-voltage (C - V), and conductance-voltage (G - V) measurements. It shows a rectifying behavior with about four order of rectification factor, and barrier height and ideality factor are calculated from the rectification curve. Dielectric parameters are determined from frequency-dependent C - V and G - V relations. The experimental results show that both of these curves are in a strong response to the frequency and bias voltage. They are found in decreasing behavior with increasing frequency, and both of them increase with increase in bias voltage although there are different increasing trends. At reversed bias voltage region, barrier potential, Fermi level energy, and interface charge carrier contribution are evaluated by using 1/C-2 - V plot. Series resistance values are also calculated under the variation of frequency and voltage. Thus, the capacitive characteristics of the diode are corrected by eliminating series resistance contribution together with the possible effect on interface charge carriers. Detailed information is obtained by determining electronic parameters affected by interface states over a wide frequency range (1 kHz to 1 MHz). At this point, strong response to the frequency is observed for the dielectric constant. Under the effect of interfacial polarization at low-frequency region, interface charge contribution to the capacitive response of the diode is obtained. Further analysis is performed on electrical modulus and impedance values derived from experimental dielectric data. Existence of interfacial layer capacitance is detailed by extracting distribution of interface charges from capacitance and conductance profiles of the diode under the effect of frequency.Article Citation - WoS: 1Citation - Scopus: 1An Empirical Analysis of the Average Plant Start-Up Size in Turkish Manufacturing Industries(Springer, 2012) Cilasun, Seyit Mumin; Gunalp, BurakMany studies have found start-up size of a firm to be an important determinant of its subsequent performance and probability of survival. The aim of this study is to investigate the determinants of average plant start-up size in 51 four-digit Turkish manufacturing industries for the period 1993-1999. The results of the study suggest that while industry characteristics such as industry growth rate and capital intensity have a positive impact on the average plant start-up size, industrial concentration, import penetration, and the change in research and development expenditures are negatively associated with the same variable. In addition, the macroeconomic environment is also an important determinant of the choice of plant start-up size. Finally, we find evidence that may indicate 'following' (herd) behavior in Turkish manufacturing industries.
