Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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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, UğurPhytoplankton 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: 2Indoor Air Co2 Concentrations and Ventilation Rates in Two Residences in İzmir, Turkey(Yıldız Teknik Üniversitesi, 2022) Taşer, Aybüke; Uçaryılmaz, Sedef; Çataroğlu, Ilgın; Sofuoğlu, Sait CemilHouses 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.Article Citation - WoS: 5Citation - Scopus: 7Bleach-Containing Automatic Toilet-Bowl Cleaners as Sources of Vocs, Associated Indoor Air Concentrations and Carcinogenic Risk(Turkish National Committee for Air Pollution Research (TUNCAP), 2020) Ayrı, İlknur; Genişoğlu, Mesut; Gaygısız, Handan; Sofuoğlu, Aysun; Sofuoğlu, Sait CemilHousehold cleaning products are sources of volatile organic compounds (VOCs). Bleach containing products are a special case because reactions occur between chloride and their organic content such as surfactants, perfumes, etc., generating VOCs. This study aimed to determine concentration of 13 VOCs in bleach-containing automatic toilet cleaners, to estimate their indoor air concentrations and associated exposure and health risk levels. Experiments with products purchased from supermarkets were conducted in 20-mL headspace vials by placing 1 g of sample with and without water. Solid-phase micro extraction with a DVB/CAR/PDMS fiber assembly was used for adsorption of VOCs from the headspace, and analyzed using a GC-MS. The median carbon tetrachloride and chloroform concentrations of the studied products ranged from 5.03 × 10?3 to 2.37 × 10?2 ?g/g and 2.53 × 10?2 to 2.37 ?g/g, respectively. The modeled 95th percentile indoor air concentrations in a 1.6 m3 bathroom with no ventilation were estimated to be 1 and 20 ?g/m3 for carbon tetrachloride and chloroform, respectively. The 95th percentile carcinogenic risk associated even with the use of the highest content product, 3.72 × 10?7 and 8.62 × 10?7 for carbon tetrachloride and chloroform respectively, were below the acceptable risk. In conclusion, automatic toilet-bowl cleaners were found to be sources of VOCs, but their emission potentials are not high to cause considerable indoor air concentrations over their suggested product lifetime. In turn, carcinogenic risks associated with inhalation exposure are below the de Minimis risk level of 10?6. © 2020