TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7149

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Department: search.filters.department.İzmir Institute of Technology. Environmental EngineeringPublisher: search.filters.publisher.Yıldız Teknik Üniversitesi

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  • Article
    Fabrication of Superhydrophilic Teos-Lactic Acid Composite Films and Investigation of Biofouling Behaviour
    (Yıldız Teknik Üniversitesi, 2022) Ervan, Tuğçe; Küçüker, Mehmet Ali; Cengiz, Uğur
    Phytoplankton and diatom microalgae species cause biofouling by adhering to the surfaces, especially in closed cultivation systems such as tubular photobioreactors. This biofilm formation blocks the sunlight; after harvesting, it is necessary to clean the reactor. This cleaning process causes loss not only for time and finance but also in terms of environmental pollution due to using toxic chemicals and excess water usage. This study aimed to investigate the reduction of the microorganism cell adhesion on the hybrid surface. To succeed in this, the composite surface of tetraethoxysilane (TEOS) and lactic acid (LA) was prepared by the sol-gel process. Then the hybrid surfaces were coated on glass slides by the dip coating method. The wettability performance of the TEOS-LA hybrid surface was investigated using contact angle measurement and light transmittance. The wettability result showed that the superhydrophilic surface having 54 mJ/m2 of surface free energy values was obtained. An increase in the lactic acid content of the composite films increased the surface free energy (SFE) values decreasing the water contact angle. A pencil hardness test characterized the mechanical strength of the surfaces, and it was determined that the hardness of the composite films was decreased by increasing the LA content of the composite films. Resultantly, it is found that the TEOS-LA superhydrophilic composite film reduces the adhesion of microalgae.
  • Article
    Citation - Scopus: 2
    Indoor Air Co2 Concentrations and Ventilation Rates in Two Residences in İzmir, Turkey
    (Yıldız Teknik Üniversitesi, 2022) Taşer, Aybüke; Uçaryılmaz, Sedef; Çataroğlu, Ilgın; Sofuoğlu, Sait Cemil
    Houses are the places where people spend most of their time. That is why indoor air quality at home is essential for public health. Sufficient ventilation is the factor to avoid accumulation of pollutants in indoor air, which include microorganisms, such as SARS-CoV-2. Therefore, adequate ventilation is needed to provide good indoor air quality for human health and reduce infection risk at home. There are no reports of residential ventilation rates in Turkey. In this study, CO2 concentrations were measured in two residences in Izmir, Turkey. Three experiments were conducted to determine background concentrations and the rate of natural ventilation with infiltration and opening windows. Results show that air exchange provided by infiltration is low for both case rooms, while adequate ventilation could be achieved with natural ventilation under the studied conditions. Infiltration provided air exchange and ventilation rates of 0.18 h-1 and 5.9 m3/h for Case 1 and 0.29 h-1 and 8.23 m3/h for Case 2, respectively. Air exchange and ventilation rates were increased to 2.36 h-1 and 76.9 m3/h for Case 1 and 1.2 h-1 and 34 m3/h for Case 2, respectively, by opening the windows. Although ventilation can be provided by opening the windows, the other factors that determine its rate, e.g., meteorological variables, cannot be controlled by the occupants. Consequently, people cannot ensure the good indoor air quality in bedrooms and sufficient reduction in transmission of pathogenic microorganisms; therefore, risk of spreading diseases such as COVID-19 at home.