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Yayın Improvement of seismic performance of precast frames with cladding panels fastened by energy dissipative steel cushions(Springer, 2021-09) Özkaynak, Hasan; Khajehdehi, Arastoo; Yüksel, Ercan; Karadoğan, Hüseyin FarukPrecast reinforced concrete panels are commonly used as wall claddings in precast buildings. The cladding panels are generally evaluated as non-structural members and are joined to structural systems via mechanical, welding, and bolted dry connections. Several failures were observed in the last seismic events in Southern Europe, which demonstrate the deficiencies of the cladding connections in terms of strength and ductility. A comprehensive research activity named SAFECLADDING was conducted in Europe to provide knowledge for proper seismic design of precast structures with cladding panels. In this context, energy dissipative steel cushions were developed and evaluated through the extensive experimental and numerical studies. Steel cushions can provide robust interaction of the structural system with the cladding panels. This paper numerically evaluates the effects of cladding panels with steel cushions on the global seismic behaviour of the buildings. An existing representative industrial building is selected to perform intensive nonlinear dynamic analyses. Analyses performed on the bare and hybrid systems showed that the hybrid system has high performance in terms of story drifts, internal forces, and deformations with respect to the bare system. The overall drifts in longitudinal and transversal directions of the building are reduced by about 78 and 54%, respectively. Average residual drifts of cladding panels and steel cushions indicated that the applied steel cushion placement scheme has a promising re-centring capability during seismic action.Yayın Dissipative dynamics and the statistics of energy states of a Hookean model for protein folding(Kluwer Academic Publishers-Plenum Publishers, 2000-07) Tüzel, Erkan; Erzan, AyşeA generic model of a random polypeptide chain, with discrete torsional degrees of freedom and Hookean spring connecting pails or hydrophobic residues, reproduces the energy probability distribution of real proteins over a very large range of energies. We show that this system with harmonic interactions, under dissipative dynamics driven by random noise, leads to a distribution of energy states obeying a modified one-dimensional Ornstein-Uhlenbeck process and giving rise Lo the so-called Wigner distribution. A tunably fine- or coarse-grained sampling of the energy landscape yields a family of distributions for the energies and energy spacings.Yayın Development of externalizing behaviors in the context of family and non-family relationships(Springer New York, 2016-02-04) Akçinar Yayla, Berna; Baydar, NazlıA longitudinal model was presented, that included reciprocal associations between physically harsh parenting by the mother, child externalizing problems, and support from the father, the extended family, and the neighbors. This transactional process was estimated for the years preceding school entry. The data were from a 4-years longitudinal and nationally representative study of 1009 children and their mothers in Turkey. The results indicated that concurrently, physically harsh parenting and child externalizing problems were strongly associated. Controlling for their within domain stability and cross-domain concurrent correlation, changes in harsh parenting and changes in child externalizing behaviors had significant reciprocal effects in early childhood, although these effects were small. These reciprocal effects were smaller for observer reported harsh parenting than maternal reports. There was a role of the mesosystem in this developmental process. Increases in the support from the father, and the extended family and the neighbors predicted declines in the child externalizing behaviors subsequently. Reciprocally, high child externalizing and maternal physically harsh parenting predicted subsequent declines in the support from these sources. These results were consistent with the hypotheses that negative mother–child relationships could spill over to the other relationships of the mothers, and that positive and supportive relationships of the mother could constitute positive role models for the child.Yayın Cation effect on gel-sol transition of kappa carrageenan(Springer, 2008-04) Pekcan, Mehmet Önder; Tarı İlgin, ÖzlemThe steady state fluorescence (SSF) technique was employed to study gel - sol transitions of kappa carrageenan in NaCl, KCl and CaCl2 solutions. Pyranine was used as a fluorescence probe for monitoring these transitions. Scattered light, I-sc and fluorescence intensity, I was monitored against temperature to determine the gel - sol (T-gs) transition temperatures and exponents. It was observed that T-gs values are strongly correlated to the NaCl, KCl and CaCl2 contents. The weight average degree of polymerization, DPw and gel fraction G, exponents (gamma and beta) were measured and found to be in accord with the classical Flory-Stockmayer Model.Yayın CSR and social marketing as enablers of recovery after the global recession: the Turkish banking industry(IGI Global, 2016-12-21) Gül, Mısra Çağla; Kaytaz, MehmetCorporate Social Responsibility (CSR) is a relatively new concept in Turkey. Leading companies including banks stress socially responsible activities in their marketing communications. The recent economic crisis put banks into the center stage again. Turkey was one of the few countries that emerged from the economic downturn relatively quickly. In the initial stages of the crisis, banks faced some criticism for protecting their self-interest more and not acting for the benefit of the society. Later, these criticisms got weaker and less frequent. This chapter examines the behavior of banks during the crisis with respect to CSR and social marketing. Particularly, the chapter analyzes how the banks behaved during the crisis and how they supported small and medium scale enterprises and local communities through CSR strategies, as well as how they utilized CSR efforts as a marketing tool. In addition, the outcome of these strategies is discussed.Yayın Did you read the news before playing the advergame? The effects of priming, persuasion knowledge and placement strength on brand attitude and recall in advergames(Inderscience Publishers, 2020-06-01) Sağkaya Güngör, AyşegülWith the advergames, marketers reach their goal of conveying their message to their target audience in an entertaining way. The study aims to find out, first, how the priming effects responses of the advergame players toward the brand. Additionally, persuasion knowledge and placement strength were investigated, along with priming. A 2 × 2 × 2 between-subjects laboratory experiment was conducted with 204 participants. Results show that priming has significant effects on brand attitude and recall. The effects were partially persistent after the introduction of persuasion knowledge. When the placement strength was introduced, it was observed significant differences on brand attitude and recall.Yayın Coupled influence of content, gradation and shape characteristics of silts on static liquefaction of loose silty sands(Elsevier Sci Ltd, 2017-10) Monkul, Mehmet Murat; Etminan, Ehsan; Şenol, AykutStatic liquefaction is a challenging problem of geotechnical engineering as its consequences are generally catastrophic when they occur on site. Previous laboratory studies focused on various factors that could influence the static liquefaction potential of silty sands. Most popular of those investigated factors are stress conditions, deposition method and fines content. The purpose of the present study is to investigate the other possible factors, of which very little is known, mainly focusing on the silt characteristics including grain size distribution, relative size, and shape effects of the silt grain matrix within the sand. Undrained monotonic triaxial compression tests were conducted on thirty sands with varying fmes contents, which were prepared by mixing three base sands (Sile Sands 20/30, 50/55, 80/100) with same geologic origin but with different gradations and three different non-plastic silts (IZ, SI and TI' silts) with different gradations and shape characteristics. The experimental results revealed that each of the mentioned factors had their own influence on static liquefaction behavior of sands. The static liquefaction potential of all the three sands in this study was observed to increase with decreasing coefficient of uniformities of the silt grain matrix (CUsiit) in sands. For a particular base sand, static liquefaction potential was observed to increase with decreasing mean grain diameter ratio (D-50.sand/d(50.silt)) due to change of silt gradation. However, shape characteristics of the silt grains are also found to be another important factor, in certain cases observed to have a greater influence than mean grain diameter ratio criterion. As an example, it was shown that at the same FC, base sand, depositional energy and consolidation stress, angular nature of TT silt potentially caused more meta-stable contacts (weaker grain contacts that promote excess pore pressure generation during shearing) within the specimens than sub-rounded SI silt, which caused specimens with TT silt to be more liquefiable than their counterparts with SI silt. Moreover, it was found that there is a coupled relationship between the fines content and investigated silt characteristics (gradation, mean size, shape effects) on the static liquefaction behavior of sands. The unexpected trend regarding the last finding is that the mentioned influence of silt characteristics (i.e. gradation, size and shape) on static liquefaction of sands becomes more considerable with decreasing fines content at loose states.Yayın Numerical modelling of energy dissipative steel cushions(Korean Soc Steel Constructiın-KSSC, 2019-08) Güllü, Ahmet; Smyrou, Eleni; Khajehdehi, Arastoo; Özkaynak, Hasan; Bal, İhsan Engin; Yüksel, Ercan; Karadoğan, Hüseyin FarukEnergy dissipative steel cushions (EDSCs) are simple units that can be used to join structural members. They can absorb a substantial amount of seismic energy due to their geometric shapes and the ductile behavior of mild steel. Large deformation capability and stable hysteretic behavior were obtained in monotonic and cyclic tests of EDSCs in the framework of the SAFECLADDING project. Discrete numerical modeling strategies were applied to reproduce the experimental results. The first and second models comprise two-dimensional shell elements and one-dimensional flexural frame elements, respectively. The uncertain points in the preparation of the models included the mesh density, representation of the material properties, and interaction between contacting surfaces. A zero-length nonlinear link element was used in the third attempt in the numerical modeling. Parameters are recommended for the Ramberg-Osgood and bilinear models. The obtained results indicate that all of the numerical models can reproduce the response, and the stiffness, strength, and unloading and reloading curves were fitted accurately.Yayın Effect of magnesium and osteoblast cell presence on hydroxyapatite formation on (Ti,Mg)N thin film coatings(Springer, 2016-07-19) Önder, Sakip; Çalıkoğlu Koyuncu, Ayşe Ceren Eren; Köse, Gamze Torun; Kazmanlı, Kürşat Muhammet; Kök, Fatma Neşe; Ürgen, MustafaTiN and (Ti,Mg)N thin film coatings were deposited on Ti substrates by an arc-physical vapor deposition technique. The effect of cell presence on hydroxyapatite (HA) formation was investigated using surfaces with four different Mg contents (0, 8.1, 11.31, and 28.49 at.%). Accelerated corrosion above 10 at.% Mg had a negative effect on the performance in terms of both cell proliferation and mineralization. In the absence of cells, Mg-free TiN coatings and low-Mg (8.1 at.%)-doped (Ti,Mg)N surfaces led to an early HA deposition (after 7 days and 14 days, respectively) in cell culture medium (DMEM), but the crystallinity was low. More crystalline HA structures were obtained in the presence of the cells. HA deposits with an ideal Ca/P ratio were obtained at least a week earlier, at day 14, in TiN and low-Mg (8.1 at.%)-doped (Ti,Mg)N compared with that of high-Mg-containing surfaces (>10 at.%). A thicker mineralized matrix was formed on low-Mg (8.1 at.%)-doped (Ti,Mg)N relative to that of the TiN sample. Low-Mg doping (<10 at.%) into TiN coatings resulted in better cell proliferation and thicker mineralized matrix formation, so it could be a promising alternative for hard tissue applications.Yayın Drying of PAAm hydrogels at various temperatures: A fluorescence study(Taylor & Francis Group, 2007-05) Aktaş, Demet Kaya; Evingür, Gülşen Akın; Pekcan, Mehmet ÖnderThe steady-state fluorescence (SSF) technique was employed for studying the drying of polyacrylamide (PAAm) hydrogels. Disc-shaped hydrogels were prepared by free-radical crosslinking copolymerization of acrylamide (AAm) with N,N'-methylene bisacrylamide (BIS) as crosslinker in the presence of ammonium persulfate (APS) as an initiator. Pyranine (P) was introduced as a fluorescence probe and the intensity of pyranine was monitored during in situ drying at various temperatures. It was observed that the fluorescence intensity of pyranine increased during the drying process. A supporting, gravimetrical experiment was also performed. A phenomenological equation was introduced to determine the desorption coefficient, D, of water molecules from the drying hydrogels at various temperatures. The desorption activation energy, triangle E-d, values were measured for the drying processes and found to be 91.08 and 36.82 kJ mol(-1) by fluorescence and gravimetrical methods, respectively. This difference most probably originates from the origin of the techniques; the fluorescence technique measures the parameters at a molecular level, whereas the gravimetrical technique measures a parameter in the bulk.
