Sürdürülebilir Kalkınma Amaçları

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Araştırmacılar(2)

• Akaltun, Yunus
• Gültekin, Hülya Eraslan

• ArticleAçık Erişim2022/r/ebyu/20616
  The Effects of LEDs with different CCT values on growth characteristics of Triticum aestivum L. (wheat) and Hordeum vulgare L. (barley)

  Osma, Etem; Elveren, Müjgan; Karagöz, Zehra; Sahin, Mustafa; Akaltun, Yunus

  Light Emitting Diode (LED)s are used extensively in almost everywhere in our daily life and they have different color temperatures such as Correlated Color Temperature (CCT) which is represented by ˚K (Kelvin). In this study, wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) were cultivated in laboratory environment under LED with different CCT values (2000, 3000, and 6000˚K). After cultivation, plant height and weight values, the quantity of chlorophyll and carotene, the amount of leakage of electrolyte and element absorption capacity from the soil, POX (Peroxidase) and SOD (Superoxide Dismutase) enzyme activities of cultivated plants were determined. Results were evaluated on Statistical Package for the Social Sciences Program (SPSS 22) and significant differences were obtained on plants which were grown at different color temperatures of light. It was concluded that measurements from plants which were grown under LED light with cold color temperatures (6000˚K) were more consistent than those of plants grown under other lights with different temperatures. It has been deduced that cold color temperatures are closer to the optimum light values required for a plant to grow faster.

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• ArticleAçık Erişim2018/r/ebyu/22436
  Determination of Mass Attenuation Coefficients of High Strength Lightweight Concrete Which Producing Using Raw Perlite Aggregate

  Yılmaz, Demet; Uzunoğlu, Zeynep; Ulusu, İsmet; Akaltun, Yunus

  The development of technology increases the environmental pollution and radiological effects. In the presentwork, the radiation effects were determined experimentally, in the high strength lightweight concreteaccording to water /cement ratio. Also, the mass attenuation coefficients of the high strength lightweightconcrete samples which producing with perlite aggregate were determined. The measurements wereperformed using a high-purity germanium detector. Ten different gamma rays energies were used. It isobserved that the mass attenuation coefficients of the concrete samples are decreasing with the increasingphoton energies. The concrete obtained with perlite aggregate can be used for protect from the radiation.

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• ArticleYalnız künye2017/r/ebyu/22737
  Harici Aydınlatma Sistemlerinin Yol Açtığı Işık Kirliliğinin Çevresel Etkilerinin İncelenmesi

  Sahin, Mustafa; Oğuz, Yüksel; Akaltun, Yunus

  Especially since the second half of the 20th century, important developments in the fields of science, industry and technology have emerged. In parallel with this development, the need to illuminate, especially to the artificial illumination, has increased. Artificial lighting systems have become almost imperative in interior spaces as well as in outdoor spaces such as parks, gardens, streets and city lighting. The most important factor that makes illuminating in outside areas a necessity is the sense of security that people feel safe. On the other side, from the ergonomic point of view, phenomenons such as selectivity and attention-grabbing have made external illumination compulsory. Nowadays, external lighting applications, which is an important part of city lighting, are not done correctly and in a planned way. The city lighting consists of parks, gardens, streets, roads, streets, sports facilities, tourist facilities, exterior lighting and security lighting systems. The problem of light pollution, which has become a big problem nowadays, has come into being when the above mentioned lighting systems are added to the lights that overflow from the internal volumes of the buildings. In the light of this information, the concepts of external lighting, correct lighting and light pollution are covered in detail. The factors that cause light pollution under the heading of outdoor lighting systems have been examined. Finally, the environmental effects of light pollution are determined by using the findings and solution proposal is presented

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• ArticleYalnız künye2016/r/ebyu/21110
  The Coating of Hydroxyapatite ( HAP ) on 316L Stainless Steel use by SILAR Method

  Çayır, Tuba; Gündogdu, Ozcan; Akaltun, Yunus

  Hydroxyapatite (HAP) has been known to be bioactive and biocompatibility due to its chemical similarity with bone minerals that is used in dental and medical applications. However, poor mechanical strength of hydroxyapatite ceramics restricts their adaptation to load bearing implants made from HAP alone. Therefore usage of HAP ceramics as a coating on metallic implants, offers greats improvement in orthopedic and dental applications.In this study, HAP coating was synthesized on implant stainless steel substrate via SILAR method. (NaPO4 12H2O) is taken as P precursor and (CaCl2 H2O) is taken as Ca precursor to obtain HAP coating. Before deposition, titanium substrates were grinding and passivated in nitric acide then washed in distilled water. Deposition process on stainless steel was carried out by dipping technique uniformly. The HA deposits were investigated by means of scanning electron microscopy (SEM), X-Ray diffraction (XRD).

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• ArticleYalnız künye2007/r/ebyu/18333
  Effective mass calculation for InSe, InSe:Er crystals

  Ates, A.; Kundakci, M.; Akaltun, Y.; Gurbulak, B.; Yildirim, M.

  Undoped indium selenide (InSe) and Er doped InSe single crystals were grown by Bridgman-Stockberger method. The InSe crystals both undoped and doped Er had no cracks or voids on the surface. No polishing or cleaning treatments were carried out on the cleaved faces of these samples because of the natural mirror-like cleavage faces. The absorption measurements were carried out in the temperature range 10-320 K and the external electric field effect on the absorption measurements is investigated. The absorption edge shifted towards to the longer wavelengths under an electric field as 6 kV/cm. Using the electric field shifting, effective mass values are calculated. (c) 2006 Elsevier B.V. All rights reserved.

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