TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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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; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPhytoplankton 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) Sofuoğlu, Sait Cemil; Uçaryılmaz, Sedef; Çataroğlu, Ilgın; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyHouses 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: 1Children in Urban Environments: a Case Study From a Dense Neighbourhood in Izmir-Turkey(Yıldız Teknik Üniversitesi, 2022) Dikmen Güleryüz, Oylum; Doğan, Fehmi; Doğan, Fehmi; Kasalı, Altuğ; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyThe aim of this study is to understand children's engagement with their urban outdoor environments in Izmir-Turkey, a city with a high urbanisation rate, and to explore the factors that affect their outdoor preferences outside of their school time. The study consists of a field study conducted in a densely populated middle-income neighbourhood. Participants are fourth-grade children from a state-run primary school aged 9-11 years (n=44) and their parents (n=40). The study followed a multi-methodological approach, employing questionnaires, drawing and story writing tasks as data collection methods. Results of the study showed the strong tendency to prefer outdoors during their free time even when their neighbourhood is a high-density urban settlement with limited opportunities for outdoor activities. In the studied neighbourhood, most of the participants mentioned the schoolyard over other locations as their preferred place fin- outdoor play. Other than the schoolyard, the children mainly reported familiar places in their neighbourhoods, close to their local environments which were also depicted in their drawings and described in their stories. From the perspectives of urban designers and policy-makers, the findings of the study highlight aspects to be concerned about opportunities for outdoor play in high-density and urbanised central neighbourhoods.Article Ultrasound Assisted Extraction for the Recovery of Phenolic Compounds From Waste Hazelnut Shell(Yıldız Teknik Üniversitesi, 2020) Yüksel Özşen, Aslı; Şengün, Duygu; Yüksel Özşen, Aslı; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyHazelnut shell is the primary byproduct of hazelnut industry which has the potential source of antioxidants, and phenolics with interest of pharmaceutical, food, and cosmetic industries. The main goal of this study is to determine effects of extraction method, extraction time, solvent type, solid to liquid ratio, and particle size on extraction yield, antioxidant capacity, and total phenolic content of waste hazelnut shell. The highest extraction yield was found as 15.4% by using methanol as solvent, in combined extraction for 16 h total extraction time. As for the best antioxidant capacity, 0.0508 mg TE mL-1 was observed by using methanol as a solvent in ultrasonic extraction, whereas the highest phenolic content was found as 0.188 mg GAE mL-1 by Soxhlet extraction with acetone for 8 h. After extraction of hazelnut shell waste, major components were found as oleic and palmitic acids for all solvent types according to GC-MS results.Article Citation - WoS: 4Impact of Window-To Surface Area for Different Window Glass Types and Wall Orientations on Building Energy Performance: a Case Study for a School Building Located in Izmir, Turkey(Yıldız Teknik Üniversitesi, 2011) Yildiz, Yusuf; Durmuş Arsan, Zeynep; Ozbalta, Trkan Goksal; Arsan, Zeynep Durmus; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyThe opaque and transparent surfaces of buildings have an important role in the total percentage of energy loss or gain. Heat loss or gain from windows are dependent on the window-to-wall area ratio, the window glass type, and the type of window frame used. In the concept of energy efficient design, heat loss or gain from windows should be analyzed in detail in the early stages of building design by considering local climatic conditions. This study investigates a school building located in Izmir in Turkey, a city with a hot and humid climate. Various glass types with different glazing characteristics and number of layers, located in different parts of the buildings and with different window-to-wall ratios are analyzed and compared using building the energy analysis program "EnergyPlus". Results indicate that window-to-wall area ratios, wall orientation and glass types are important factors in the building's total energy consumption. When the window-to-wall area ratio is increased from 10% to 60%, the winter heating load of the building decreases in maximum amount on the south side of the building and reduces in minimum amount on the east side of the building. When summer cooling load is investigated the highest increase in energy consumption is found on the south side of the building. On the eastern and western sides of the building the effect of increased energy consumption value remains low. When the total energy consumption (cooling + heating) is considered, it is calculated that the east and west sides have the biggest total effect and the northern wall has the smallest total effect. When low emissivity glass is used instead of double layer glass, in terms of energy consumption the building side order of effect remains the same, although actual values differ. It is therefore clear that using energy analysis programs to analyse different factors within the energy consumption of buildings will be beneficial in creating energy efficient solutions. This can be carried out in the earlier stages of the architectural design of the buildings or at the renovation stages of existing buildings.Article Citation - WoS: 7Investigation of Educational Buildings in Terms of Daylighting Performance(Yıldız Teknik Üniversitesi, 2011) Kazanasmaz, Zehra Tuğçe; Aral, Duygu; Kazanasmaz, Tugce; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyEducational buildings have the priority among other building types in daylight performance studies. There are several reasons for this. Classrooms which are used during the whole day should have sufficient and homogeneously distributed daylight. In insufficient daylight conditions, the use of electrical lighting increases energy consumption. Users' visual comfort should also be assured, and design incorporating natural light requires the analysis of sun protection devices in order to avoid glare and excessive heat. Also, atriums and skylights can be included in the building design with the aim of distributing light equally and in a relatively balanced manner throughout the building. However, lighting schemes are often proposed by architects and professionals who tend to make use of different design tools, and it would be pertinent to investigate whether these tools perform as desired. This study analyses daylight design principles and design elements in educational buildings. It outlines the method which has been used to analyse the daylight performance of buildings. A university building was selected for the field study. Measurements were taken in sample spaces to determine daylight performance. Utilising comparison between standard values and measured values, findings are presented in the form of tables, drawings and figures.Article A Fuzzy Logic Model To Classify Design Efficiency of Nursing Unit Floors(Yıldız Teknik Üniversitesi, 2010) Kazanasmaz, Zehra Tuğçe; Tayfur, Gökmen; 02.02. Department of Architecture; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThis study was conducted to determine classifications for the planimetric design efficiency of certain public hospitals by developing a fuzzy logic algorithm. Utilizing primary areas and circulation areas from nursing unit floor plans, the study employed triangular membership functions for the fuzzy subsets. The input variables of primary areas per bed and circulation areas per bed were fuzzified in this model. The relationship between input variables and output variable of design efficiency were displayed as a result of fuzzy rules. To test existing nursing unit floors, efficiency output values were obtained and efficiency classes were constructed by this model in accordance with general norms, guidelines and previous studies. The classification of efficiency resulted from the comparison of hospitals.Article Citation - WoS: 2The Development of Western-Type Large-Scale Consumption Areas in Turkey and Legal and Structural Regulation Efforts in Urban Retail Environments(Yıldız Teknik Üniversitesi, 2009) Kompil, Mert; Celik, Murat; 01. Izmir Institute of TechnologyThe retail sector has been experiencing a rapid and continuous change worldwide. There have also been profound changes in Turkey, especially after the 1980s. Both the retail sector and the urban retail environments have been altered radically. One of the most significant indicators of this change is the proliferation of western-type large-scale retail developments. Past experiences in developed countries have shown that the uncontrolled development of large-scale retail areas results in some undesired socioeconomic and physical outcomes, such as decline in the cultural and commercial activities of city centers, damage in existing retail workforce structure, and change in local retail hierarchy, nearby land uses, traffic loads and original architectural identity. Many countries have put into practice restrictive and regulatory policies to prevent these negative effects. As similar transformations have also been realized in Turkish retail environments, many institutions think that similar legal regulations must be implemented in Turkey as well. The present study investigates the ongoing retail change within the Turkish context, explores the legal and structural regulatory policies of the Organization for Economic Co-operation and Development (OECD) countries, and critically discusses the appropriate retail regulation policies for Turkey.Article Efficient Design of Nursing Unit Floors(Yıldız Teknik Üniversitesi, 2009) Kazanasmaz, Zehra Tuğçe; Duzgunes, Arda; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyHospital designs aim to obtain the lowest possible construction, maintenance and operational costs together with patient satisfaction, comfort and privacy. To satisfy these needs, the efficient design of nursing unit areas becomes considerably important. This study was thus conducted to analyze planimetric design efficiency of nursing unit floors by defining certain floor areas and floor area ratios. To test existing nursing unit floors, quantitative assessments were noted in regard to their planimetric efficiency: the utility value of the built floor area, both in terms of its allocation to patient space (served), support (serving) and circulation space and the relative proportions of these. Results were presented in a comparative table. Of the 15 hospital floor plans analyzed, five satisfied minimum space requirements for patient areas, while another five were in the optimum range for circulation areas. Two were defined as the least efficient, having the lowest patient-to-circulation area ratio.Article Citation - WoS: 3Citation - Scopus: 4The Effect of Cooling on Mechanical and Thermal Stresses in Vascular Structures(Yıldız Teknik Üniversitesi, 2018) Çetkin, Erdal; Çetkin, Erdal; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyHere, we show how the vascular channel configuration and its shape affect the mechanical strength which is simultaneously subjected to heating and mechanical load. The material properties were defined as functions of temperature. The effect of channel cross-section on the coolant mass flow rate, peak temperature and peak stresses are documented. The results show that the resistances to flow of stresses and fluid is minimum with the circular channels while the resistance to the heat flow is the smallest with semi-circular channels. In addition, morphing the vascular design provides almost the smallest resistance to the heat flow with circular channels (0.3% difference in the peak temperature). This shows that even the convective resistances are the smallest with circular-cross section, overall thermal resistance is smaller in semi-circular design for the fixed fluid volume. The peak stress is smaller with hybrid design than the parallel designs for the entire pressure drop range. In addition, the effects of mechanical load, heating rate and reference temperature on the stress distribution are also documented. Furthermore, the thermal and mechanical stresses are also documented separately, and then compared with the coupled solution cases. The chief result of this paper is that for a coupled system minimizing only one of the resistance terms is not sufficient, all the resistances considered simultaneously in order to uncover the best performing design. In coupled solutions, we documented the simulation results with temperature dependent material properties and the resistances to the heat and fluid flow is affected by the mechanical deformations. In addition, the results show that the designs should be free to vary, the unexpected designs can be the best performing designs for the given parameters and constraints. Therefore, the design parameters based on the experience does not always yield the best performing designs as the objectives and constraints vary.