In this paper, the steps in the production process of forming hybrid composite coatings on surface of the ZA-27 alloy known as a sliding bearing material, and analysis of surface morphology of the coated samples were investigated. The process includes forming an electrolytic solution with solid lubricant particles content in a stainless steel tank and coating procedures that called micro arc oxidation (MAO). The substrate materials used in this study are commercial ZA-27 alloy that produced by using die-casting method. Two different electrolytic solutions were used for the surface coating process. Electrolytic solutions include solid lubricant particles (graphite and hexagonal boron nitride (h-BN)). The results showed that both graphite/Al2O3 and h-BN/Al2O3 hybrid composite coating were successfully grown on surface of the ZA-27 alloy. The structural and chemical compositions of the both coated samples were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffraction (XRD). In the meantime, coating thickness were also determined.
Pile up and dead time are two important corrections in the analysis of X-ray and gamma ray spectra. The most important of these is pile up correction because these peaks do not really exist in the spectra; they only seem to exist. For this reason, these peaks affect both the qualitative and quantitative accuracy of the analysis. In addition, the pile up pulses forming the pile up peaks increase the background count in the spectrum. Companies that produce X-ray or gamma ray detector systems design pile up reject circuits and integrate them into detector systems to prevent these pulses. These circuits have time limitations because they are made up of electronic devices. For this reason, the pile up problem cannot be solved completely in these circuits. Therefore, mathematical models based on a statistical approach are needed. Such a model was developed in this study. A computer program based on this model was developed. This developed program has been applied to X-ray and gamma ray spectra. It has been shown that this model provides about 2% correction in the main peak regions and significantly reduces background counts.
Bu araştırma, öğretmen adaylarının sürdürülebilir kalkınma ve küresel iklim değişikliği farkındalıkları arasındaki ilişkiyi inceleyerek, eğitim süreçlerine yönelik önemli bulgular sunmayı amaçlamaktadır. Araştırma, tanımlayıcı ve ilişkisel bir model doğrultusunda gerçekleştirilmiştir. Çalışmada kullanılan Küresel İklim Değişikliği Farkındalık Ölçeği (KİDFÖ) ve Sürdürülebilir Kalkınma Farkındalık Ölçeği (SKFÖ), önceki çalışmalarda geçerlilik ve güvenilirliği onaylanmış, literatürde sıkça başvurulan ölçüm araçlarıdır. Veriler, basit rastgele örnekleme yöntemiyle seçilen 355 öğretmen adayından çevrimiçi anket aracılığıyla toplanmıştır. Araştırma bulguları, öğretmen adaylarının KİDFÖ puanlarının ortalama 50 (orta düzey), SKFÖ puanlarının ise ortalama 90 (orta düzey) olduğunu göstermektedir. Korelasyon analizi sonuçlarına göre, küresel iklim değişikliği farkındalığı ile sürdürülebilir kalkınma farkındalığı arasında orta düzeyde, pozitif yönlü ve anlamlı bir ilişki bulunmuştur (r=0,566, p
Changes in climatic conditions have ecological and economic consequences or impact for trees and forest stands. In this respect, it is crucial to understand the radial growth trends of trees, their ecological response across elevation gradients, and the possible impacts of climate change on the species. In this study, Picea orientalis (L.) Peterm, located in the Fırtına Creek Basin in the northern part of the Eastern Black Sea Mountains in northeastern Turkey, was investigated along different elevation gradients in the context of climate-growth response. In the study, six site chronologies along an elevation gradient from 900 m to 2050 m were developed. Dendroclimatological methods were applied to assess the elevation-dependent radial growth characteristics of trees. In total, 200 increment cores were collected from 98 living trees. The relationships between climate and tree ring growth along the elevation gradient showed a positive relationship between growth and temperature at upper elevations (1700–1900 m) and a positive relationship between growth and precipitation at middle elevations (1400–1600 m). In particular, January–April mean temperatures and May rainfall were positively correlated with tree-ring growth. At lower elevations (900–1100 m), the correlation coefficients between climate and growth are insignificant because, at these altitudes, the species have optimum ecological conditions. It was also found that mean temperatures between 0 °C and 2 °C in January–April and total precipitation between 60 and 100 mm in January–February positively affect tree growth. However, if these thresholds are exceeded, it is possible that growth may be adversely affected. This research underscores the complex interplay between climate variables and tree growth along elevation gradients, highlighting the need for adaptive management strategies in the face of changing climatic conditions.
