• Title/Summary/Keyword: Sakarya

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Flexural strengthening of RC Beams with low-strength concrete using GFRP and CFRP

  • Saribiyik, Ali;Caglar, Naci
    • Structural Engineering and Mechanics
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    • v.58 no.5
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    • pp.825-845
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    • 2016
  • The Turkish Earthquake Code was revised in 1998 and 2007. Before these Codes, especially 1998, reinforced concrete (RC) beams with low flexural and shear strength were widely used in the building. In this study, the RC specimens have been produced by taking into consideration the RC beams with insufficient shear and tensile reinforcement having been manufactured with the use of concrete with low strength. The performance of the RC specimens strengthened with different wrapping methods by using of Carbon Fibre Reinforced Polymer (CFRP) and Glass Fibre Reinforced Polymer (GFRP) composites have been examined in terms of flexural strength, ductility and energy absorption capacity. In the strengthening of the RC elements, the use of GFRP composites instead of CFRP composites has also been examined. For this purpose, the experimental results of the RC specimens strengthened by wrapping with CFRP and GFRP are presented and discussed. It has been concluded that although the flexural and shear strengths of the RC beams strengthened with GFRP composites are lower than those of beams reinforced with CFRP, their ductility and energy absorption capacities are very high. Moreover, the RC beams strengthened with CFRP fracture are more brittle when compared to GFRP.

Conus Medullaris Levels on Ultrasonography in Term Newborns : Normal Levels and Dermatological Findings

  • Asil, Kiyasettin;Yaldiz, Mahizer
    • Journal of Korean Neurosurgical Society
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    • v.61 no.6
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    • pp.731-736
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    • 2018
  • Objective : Ultrasonography (US) is the most non-invasive, safe, and, especially in the period of infancy, best method for visualizing and examining the spinal cord. Furthermore, US is the primary work-up for development of the spinal canal, and for follow-up on issues relating to subcutaneous tissues, bone development, and the spinal cord. Conus medullaris terminates at the second lumbar vertebra, according to a consensus in the literature. Methods : Healthy children under the age of 6 months who were admitted to the radiology clinic for routine USG follow-ups between the dates of March 2012 to December 2014 were included in this study. Results : Our study includes data from 1125 lumbosacral ultrasounds. The terminal point of the conus level of the attended infants, superior, middle part, inferior of the vertebrae L1, L2, and L3. Furthermore, the termination of the discal distance ratio did not differ significantly between genders. Conclusion : Therefore, according to our results, gender is not an influencing factor in the termination of the spinal cord. Based on the study we performed, as well as the previous literature, in infants without a recognized spinal pathology, the spinal cord is detected below the vertebra L3.

Enrichment of poultry manure with biomass ash to produce organomineral fertiliser

  • Dede, Omer Hulusi;Ozer, Hasan
    • Environmental Engineering Research
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    • v.23 no.4
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    • pp.449-455
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    • 2018
  • In this study, the contribution of hot biomass ash to enrichment of the mineral content and to reducing the moisture content of broiler poultry manure was investigated. For this purpose, the mixtures have been prepared by adding biomass ash at varying rates (10%, 20%, 30%, 40% and 50%) and at different temperatures ($100^{\circ}C$, $150^{\circ}C$, $200^{\circ}C$ and $250^{\circ}C$) according to the dry matter content (74.77%) of the poultry manure. The results showed that incorporation of biomass ash into poultry manure at 50% at $250^{\circ}C$ reduced the moisture content from 25.23% to 9.82%. Regarding the maximum N in the final product, the ideal temperature of biomass ash has been obtained at $150^{\circ}C$. The highest nutrient contents were obtained at 50% biomass ash incorporation. The highest dose of biomass ash application had significantly increased nutrients, such as Ca (19.34%), K (4.03%), Fe (1,545 mg/kg), Mn (812 mg/kg) and Zn (479 mg/kg) in the final organomineral fertiliser formulation. Overall, it was concluded that the addition of hot biomass ash can dramatically decrease the moisture content of poultry manure and therefore provide odour and pathogen removal and increase its plant nutrient content.

Removal of ciprofloxacin from aqueous solution by activated carbon prepared from orange peel using zinc chloride

  • Koklu, Rabia;Imamoglu, Mustafa
    • Membrane and Water Treatment
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    • v.13 no.3
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    • pp.129-137
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    • 2022
  • In this study, the removal of Ciprofloxacin (CPX) from aqueous solutions was investigated by a new activated carbon adsorbent prepared from orange peel (ACOP) with chemical activation using ZnCl2. The physicochemical properties of orange peel activated carbon were characterized by proximate and ultimate analysis, scanning electron microscopy, BET surface area determination and Fourier transformation infrared spectroscopic studies. According to Brunauer-Emmett-Teller isotherm and non-local-density functional theory, the cumulative surface area, pore volume and pore size of ACOP were determined as 1193 m2 g-1, 0.83 cc g-1 and 12.7 Å, respectively. The effects of contact time, pH, temperature and ACOP dose on the batch adsorption of CPX were studied. Adsorption equilibrium data of CPX with ACOP were found to be compatible with both the Langmuir and Freundlich isotherms. CPX adsorption capacity of ACOP was calculated as 181.8 mg g-1 using Langmuir isotherm. The CPX adsorption kinetics were found to be harmonious with the pseudo-second-order kinetic model. Conclusively, ACOP can be assessable as an effective adsorbent for the removal of ciprofloxacin (CPX) from aqueous solutions.

Secure SLA Management Using Smart Contracts for SDN-Enabled WSN

  • Emre Karakoc;Celal Ceken
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.11
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    • pp.3003-3029
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    • 2023
  • The rapid evolution of the IoT has paved the way for new opportunities in smart city domains, including e-health, smart homes, and precision agriculture. However, this proliferation of services demands effective SLAs between customers and service providers, especially for critical services. Difficulties arise in maintaining the integrity of such agreements, especially in vulnerable wireless environments. This study proposes a novel SLA management model that uses an SDN-Enabled WSN consisting of wireless nodes to interact with smart contracts in a straightforward manner. The proposed model ensures the persistence of network metrics and SLA provisions through smart contracts, eliminating the need for intermediaries to audit payment and compensation procedures. The reliability and verifiability of the data prevents doubts from the contracting parties. To meet the high-performance requirements of the blockchain in the proposed model, low-cost algorithms have been developed for implementing blockchain technology in wireless sensor networks with low-energy and low-capacity nodes. Furthermore, a cryptographic signature control code is generated by wireless nodes using the in-memory private key and the dynamic random key from the smart contract at runtime to prevent tampering with data transmitted over the network. This control code enables the verification of end-to-end data signatures. The efficient generation of dynamic keys at runtime is ensured by the flexible and high-performance infrastructure of the SDN architecture.

ON CHARACTERIZATIONS OF SPHERICAL CURVES USING FRENET LIKE CURVE FRAME

  • Eren, Kemal;Ayvaci, Kebire Hilal;Senyurt, Suleyman
    • Honam Mathematical Journal
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    • v.44 no.3
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    • pp.391-401
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    • 2022
  • In this study, we investigate the explicit characterization of spherical curves using the Flc (Frenet like curve) frame in Euclidean 3-space. Firstly, the axis of curvature and the osculating sphere of a polynomial space curve are calculated using Flc frame invariants. It is then shown that the axis of curvature is on a straight line. The position vector of a spherical curve is expressed with curvatures connected to the Flc frame. Finally, a differential equation is obtained from the third order, which characterizes a spherical curve.

On Ruled Surfaces with a Sannia Frame in Euclidean 3-space

  • Senyurt, Suleyman;Eren, Kemal
    • Kyungpook Mathematical Journal
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    • v.62 no.3
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    • pp.509-531
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    • 2022
  • In this paper we define a new family of ruled surfaces using an othonormal Sannia frame defined on a base consisting of the striction curve of the tangent, the principal normal, the binormal and the Darboux ruled surface. We examine characterizations of these surfaces by first and second fundamental forms, and mean and Gaussian curvatures. Based on these characterizations, we provide conditions under which these ruled surfaces are developable and minimal. Finally, we present some examples and pictures of each of the corresponding ruled surfaces.

REPDIGITS AS DIFFERENCE OF TWO PELL OR PELL-LUCAS NUMBERS

  • Fatih Erduvan;Refik Keskin
    • Korean Journal of Mathematics
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    • v.31 no.1
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    • pp.63-73
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    • 2023
  • In this paper, we determine all repdigits, which are difference of two Pell and Pell-Lucas numbers. It is shown that the largest repdigit which is difference of two Pell numbers is 99 = 169 - 70 = P7 - P6 and the largest repdigit which is difference of two Pell-Lucas numbers is 444 = 478 - 34 = Q7 - Q4.