Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2010 - 20203

Settings

Language: search.filters.language.enSubject: search.filters.subject.Statistical analysis

Search Results

Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 23
    Citation - Scopus: 26
    Experimental and Statistical Analysis of Carbon Fiber/Epoxy Composites Interleaved With Nylon 6,6 Nonwoven Fabric Interlayers
    (SAGE Publications Inc., 2020) Beylergil, Bertan; Tanoğlu, Metin; Beylergil, Bertan; Tanoğlu, Metin; Aktaş, Engin; 03.10. Department of Mechanical Engineering; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Thermoplastic interleaving is a promising technique to improve delamination resistance of laminated composites. In this study, plain-weave carbon fiber/epoxy composites were interleaved with nylon 6,6 nonwoven fabrics with an areal weight density of 17 gsm. The carbon fiber/epoxy composite laminates with/without nylon 6,6 nonwoven fabric interlayers were manufactured by VARTM technique. Double cantilever beam fracture toughness tests were carried out on the prepared composite test specimens in accordance with ASTM 5528 standard. The experimental test data were statistically analyzed by two-parameter Weibull distribution. The results showed that the initiation and propagation fracture toughness Mode-I fracture toughness of carbon fiber/epoxy composites could be improved by about 34 and 156% (corresponding to a reliability level of 0.50) with the incorporation of nylon 6,6 interlayers in the interlaminar region, respectively. The results also revealed that the percent increase in the propagation fracture toughness value was 67 and 41% at reliability levels of 0.90 and 0.95, respectively.
  • Article
    Citation - WoS: 28
    Citation - Scopus: 32
    Describing the Karst Evolution by the Exploitation of Hydrologic Time-Series Data
    (Springer Verlag, 2015) Katsanou, K.; Lambrakis, Nicolaos J.; Tayfur, Gökmen; Baba, Alper; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The importance of the groundwater management of karst aquifers relatively to their complexity requires the knowledge of the subsurface flow and storage behavior. In this study, a methodological approach based on the exploitation of daily spring’s discharge data was developed and tested. The methodology makes use of the hydrograph recession curves, the correlograms output, and the logarithmically structured duration curves. This methodological approach was applied to the complex karst system of Louros basin. The Louros karst system consists of individual karst units discharged by respective springs which are distributed on three levels and form three easily distinguishable groups. The application results revealed a well organized karst system with conduits of slow and fast flow. It also revealed the uniformity and the complexity of the different units, as well as the properties, such as the storativity and the evolutionary process. This approach demonstrates the benefits of interpreting different methods in a hydrologically meaningful way for the recharge data evaluation.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    Carbon Nanotube Diameter Tuning Using Hydrogen Amount and Temperature on Sio2/Si Substrates
    (Springer Verlag, 2010) Aksak, Meral; Selamet, Yusuf; Selamet, Yusuf; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Carbon nanotubes (CNTs) were grown on thin iron (Fe) films on SiO 2/Si substrates by chemical vapor deposition (CVD) at four different hydrogen (H2)/methane (CH4) ratios at temperatures ranging from 925 to 1000°C. The effects of temperature and the amount of hydrogen gas on the mean diameter at increasing temperature were examined. We demonstrated that the mean diameter and its distribution depend not only on temperature but also on the H2 amount. We showed that increasing H2 amount strongly affects the structure of CNTs, especially at high growth temperature; the mean diameter at 1000°C reduced from about 383 to 34 nm by increasing H2 amount from 24 to 50 sccm. We observed that at high temperature growth the mean diameter was decreasing very fast initially with increasing H2 amount suggesting the dominance of H2 over the growth temperature. A decrease in the slope of diameter vs. H 2 amount with further increment in H2 amount implied that the temperature was, then, deciding the CNT diameter through catalyst particle coarsening. The statistical analysis presented implies that the H2 amount has to be adjusted according to the growth temperature for given CH 4 amount to keep CNT diameter under control, and the large diameter distributions at high temperature and high H2 amount can be associated with the large variation in the catalyst particle sizes. © 2010 Springer-Verlag.