The investigation of interfaces of multiaxis fiber reinforced composites by fiber bragg grating sensors

Advanced Composites, due to their high strength to weight ratio, replaced conventional materials in many applications. The role of structural health monitoring (SHM) in development of advanced composites is proved by many in industry and academia. In this thesis work, vacuum infusion and resin transfer molding (RTM) were developed for advanced composite production. Within the context of advanced composite development project, a fully functioning mechanical test laboratory is built in Yonca-Onuk JV shipyard and also fundamental composite configurations were subjected to mechanical tests. In the last stage, interply hybrid composite configurations that can be used for advanced composites were tested with embedded fiber Bragg grating (FBG) sensors

Is there an association between two-STAT4 gene polymorphisms and rheumatoid arthritis in turkish population?

[No Abstract Available

Determination of antimony by using a quartz atom trap and electrochemical hydride generation atomic absorption spectrometry

The analytical performance of a miniature quartz trap coupled with electrochemical hydride generator for antimony determination is described. A portion of the inlet arm of the conventional quartz tube atomizer was used as an integrated trap medium for on-line preconcentration of electrochemically generated hydrides. This configuration minimizes transfer lines and connections. A thin-layer of electrochemical flow through cell was constructed. Lead and platinum foils were employed as cathode and anode materials, respectively. Experimental operation conditions for hydride generation as well as the collection and revolatilization conditions for the generated hydrides in the inlet arm of the quartz tube atomizer were optimized. Interferences of copper, nickel, iron, cobalt, arsenic, selenium, lead and tin were examined both with and without the trap. 3(1 limit of detection was estimated as 0.053 mu g 1(-1) for a sample size of 6.0 ml collected in 120 s. The trap has provided 18 fold sensitivity improvement as compared to electrochemical hydride generation alone. The accuracy of the proposed technique was evaluated with two standard reference materials; Trace Metals in Drinking Water, Cat # CRM-TMDW and Metals on Soil/Sediment #4, IRM-008

The performance of embedded fiber Bragg grating sensors for monitoring failure modes of foam cored sandwich structures under flexural loads

In this study, failure modes of foam core sandwich composites are investigated by using embedded Fiber Bragg Grating sensors. Sandwich specimens with Fiber Bragg Grating sensors, embedded inside the face sheet, are manufactured using vacuum infusion process and then subjected to a static and a cyclic loading under the three-point bending mode. Different failure modes are monitored utilizing the wavelength shift and the spectrum of Fiber Bragg Grating sensors. It is shown that the responses of the Fiber Bragg Grating sensor differ depending on damage modes thereby making structural health monitoring of sandwich structures possible

The performance of embedded fiber Bragg grating sensors for monitoring failure modes of foam cored sandwich structures under flexural loads

In this study, failure modes of foam core sandwich composites are investigated by using embedded Fiber Bragg Grating sensors. Sandwich specimens with Fiber Bragg Grating sensors, embedded inside the face sheet, are manufactured using vacuum infusion process and then subjected to a static and a cyclic loading under the three-point bending mode. Different failure modes are monitored utilizing the wavelength shift and the spectrum of Fiber Bragg Grating sensors. It is shown that the responses of the Fiber Bragg Grating sensor differ depending on damage modes thereby making structural health monitoring of sandwich structures possible

Comparison of Fresh and Dried Flathead Grey Mullet (Mugil cephalus, Linnaeus 1758) Caviar by Means of Proximate Composition and Quality Changes during Refrigerated Storage at 4 +/- 2 degrees C

WOS: 000306092100001The aim of this research was to compare the differences in shelf life and resistance to decomposition of fresh and dried caviar produced from flathead grey mullet (Mugil cephalus, Lin. 1758) caught from Homa Lagoon, which is located 20 km northeast of Izmir Bay, Turkey. The proximate compositions of caviars were determined as follows: moisture 50.2+/-0.15 %, crude fat 13.1+/-0.23 %, protein 25.7+/-0.43 %, ash 1.48+/-0.03 % and carbohydrate 9.59+/-0.10 %, for fresh caviar and moisture 26.3+/-0.53 %, crude fat 13.3+/-1.51 %, protein 41.8+/-0.56%, ash 4.68+/-0.11 % and carbohydrate 14.0+/-0.05 % for dried caviar. The proximate composition values of dry and fresh caviars were significantly different (P<0.05). To determine the refrigerated shelf life, chemical quality control analysis using Total Volatile Basic Nitrogen (TVB -N), Trimethylamine (TMA) and Thiobarbituric Acid (TBA), pH and color values were measured. Both fresh and dried samples were found to be spoiled end of the 8th day of refrigerator storage, based on their TMA-N and TVB-N values