IYTE GCRIS Database (Izmir Institute of Technology)
Not a member yet
11968 research outputs found
Sort by
The Compaction Behavior of Magnesium-Expanded Natural Graphite Powder Mixtures: Tensile Strengths of Compacted Pellets
No full textThe effects of Expanded Natural Graphite (ENG) content, powder mixing method and compaction pressure on the tensile strengths of Magnesium AZ91 (9 wt% Al, 1 wt% Zn and 0.2 wt% Mn) + ENG powder mixture pellets were investigated. The tensile strengths of the pellets increased with an increase in the ENG content and compaction pressure and also with the applied powder ball milling. However, the compaction pressures above 500 MPa resulted in shear banding
İyte Kütüphanesi Neler Yapıyor?
No full text60. Kütüphane Haftası kapsamında 29 Mart 2024 tarihinde Yaşar Üniversitesi Kütüphanesi ev sahipliğinde gerçekleştirilen "Akademik Kütüphaneler İzmir: Biz Ne Yapıyoruz?" başlıklı panel kapsamında yapılan sunumdur
Recovery of Metals From Leach Liquors: Biosorption Versus Metal Sulfide Precipitation
No full textExtraction of metals (leaching) is chemical or biochemical processes that utilize acids or microorganisms to enhance the suspension of metals from the primary and secondary sources by making them more amenable to dissolution in aqueous solutions (leachate). Recovery of metals from the leachates is an essential stage supported by additional purification processes such as precipitation of impurities, electrowinning, solvent extraction, chemical or biological adsorption, and ion exchange. In this study, especially biosorption and metal sulfide precipitation are overviewed and discussed. Biosorption is a process by which particular biomass such as bacteria, fungi, yeast, agricultural wastes, algae, and biowastes can able to bind with specific ions or other molecules from aqueous solutions. Metal sulfide precipitation can be highly effective in obtaining a high degree of separation of metal cations from complex leachates. Each of these techniques has advantages and drawbacks. Sometimes, a technique may not be effective in attaining higher metal recovery. Therefore, different recovery techniques are needed to recover the target elements from the complex leachates. Maybe a combination of two or three recovery techniques is required to recover metals from complex leachates. Additionally, the research activity highlighted that metal sulfide precipitation and biosorption processes have to limit factors that could hinder the process scale-up. Thus, more research is needed to evaluate the environmental impacts of metal recovery from leach liquors. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024
Microbial Desalination Cell Treated Spent Geothermal Brine as a Nutrient Medium in Hydroponic Lettuce Cultivation: Health Risk Assessment
No full textThe scarcity and contamination of freshwater resources are extremely critical issues today, and the expansion of water reuse has been considered as an option to decrease its impact. Therefore, the reuse of microbial desalination (MDC)-treated spent geothermal brine for agricultural purposes arises as a good solution to prevent water contamination and provide sustainable water usage. In this study, the potential of treated spent geothermal water from MDC system as a nutrient solution for the hydroponic cultivation of lettuce was evaluated. The effects of different water samples (Hoagland solution (R1) as a control, MDC-treated water (R2), 1:1, v/v mixture of MDCtreated water and Hoagland solution (R3), 4:1, v/v mixture of MDC-treated water and Hoagland solution (R4), and tap water (R5)) on lettuce growth were considered. The application of R3 and R4 samples for hydroponic lettuce cultivation was promising since the lettuce plants uptake sufficient nutrients for their growth and productivity with low toxic metal concentrations. In addition, the chlorophyll-a, chlorophyll-b, and carotene contents of lettuce were in the range of 1.045-2.391 mg/g, 0.761-1.986 mg/g, and 0.296-0.423 mg/g in different water samples, respectively. The content of chlorophyll-a was highest in R1 (2.391 mg/g), followed by R3 (2.371 mg/g). Furthermore, the health risk assessment of heavy metal accumulations in the lettuce plants cultivated in the various water samples was determined. Results showed that heavy metal exposure via lettuce consumption is unlikely to suffer noticeable adverse health problems with values below the permissible limit value
Exploring Quantitative Analysis of Thermal Comfort in Architecture as a Positivist Research Paradigm
No full textLithium Extraction From Geothermal Brine Using Γ-Mno2: a Case Study for Tuzla Geothermal Power Plant
No full textGeothermal brines contain high concentrations of ions and form a source of various valuable elements. The isolation of the elements from their water systems is a great challenge when the gradual depletion of ores in mining is considered. Attempts have been made for a long time to isolate valuable elements from aqueous mixtures prepared in the laboratory. However, those studies might not reflect the complexity of natural systems and might yield results that deviate significantly from the performance in real field systems. In this study, sorption is used to extract lithium ions from a representative field, Tuzla Geothermal Power Plant (TGPP) Turkey, using a mini-pilot reactor introduced to the reinjection well of the plant. Electrolytic manganese dioxide (γ-MnO2), a relatively inexpensive material widely used as the cathode material in lithium-ion batteries, was employed as a sorbent material for lithium. The sorption/desorption performance of the novel γ-MnO2 was investigated under various conditions. Sorption is performed at 360K and 2 bars. The maximum sorption performance was obtained at 1 h in Tuzla GPP. The desorption experiments were performed in acidic solutions. The concentration of Li+ in the desorption solution was found to be 25 mg/L on average when 10 g of γ-MnO2 was dispersed into 30 mL of the acidic aqueous solution. The first desorption solution was used consecutively for collecting more Li+ ions through the desorption of fresh brine-treated powder samples (cumulative desorption). By repeating this process four times consecutively, 230 mg/L of Li+ was obtained in the desorption solution. Moreover, the reusability of the γ-MnO2 sorbent was examined. The sorbent powder showed almost 40% performance efficiency compared to virgin powder under the conditions employed in this study. The use of electrolytic γ-MnO2 sorbent for lithium adsorption was found to be a promising process for practical use in the separation of lithium from geothermal brines. © 202
The Uncertain Certainty of a Nightmare: What If Another Destructive Earthquake Strikes Izmir (türkiye)?
No full textOn 6 February 2023, near Kahramanmaras in south-central Turkiye, an event underscored the vulnerability of cities to seismic activity, revealing a lack of preparedness for substantial shocks. The contributing factors are manifold, yet fundamentally, the collapse of buildings and infrastructure can be attributed to an underestimated capacity for meticulous settlement planning (location) and the adoption of advanced techniques for resilient construction (structure). Regrettably, as has been investigated by many research works, ordinary urban planning in Turkiye hardly finds ways to integrate the vulnerability analysis for settlement expansion, which includes the full integration of geological characteristics with the analysis of building sensitivity. With this work, we wanted to build a composite risk index based on earthquake vulnerability, hazard amplification map, and exposure. We designed the composite index in Izmir's basin, Turkiye's third most populated city, to answer the question: What if a destructive earthquake strikes this densely settled area? The results illustrates how the coupled integration of digital data on geology with settlements and infrastructure in a Geographic Information System environment can be used to produce risk maps and plan the anthropic system's adaptation carefully. Findings demonstrate the city is highly vulnerable to earthquakes and identify priority areas for planning intervention, relocation, and renovation of buildings
Spatial Graphoids
No full textTo study knotted graphs with open ends arising in proteins, we introduce virtual graphoids, which are virtual spatial graph diagrams with two distinguished degree-one vertices modulo graph Reidemeister moves applied away from the distinguished vertices. Generalizing previously known results, we give topological interpretations of graphoids. By analyzing the Yamada polynomial, we provide bounds for the crossing numbers. As an application, we can produce nontrivial graphoids by verifying that they satisfy adequacy conditions in the same spirit as Lickorish and Thistlethwaite’s notion of adequate links. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2023
Software Change Size Measurement: an Exploratory Systematic Mapping Study
No full textChange in software projects can occur through various channels. Customers may request modifications or new features; appraisal activities such as reviews or testing may uncover issues that necessitate adjustments, or products may need to adapt to changes in their operating environment. Therefore, it is essential to assess these changes explicitly and objectively within the scope of software engineering activities. Specifically, quantifying change by measuring its size is crucial for successful management, as without a meaningful metric, it is impossible to accurately assess its impact on the project's effort, schedule, and cost. This study aims to explore the concept of change in software engineering literature, with a particular emphasis on the methods used to measure its size. The study reveals that the current literature on this topic is still in its early stages and the measurement and estimation of changes remain challenging throughout both development and maintenance phases. According to the reviewed articles, size is primarily used for effort estimation. Various software artifacts from different stages of the Software Development Life Cycle (SDLC) serve as input for change measurement, highlighting the need for a versatile size measurement applicable across all SDLC phases. Most of the reviewed articles interpret change in the context of maintenance activities. This research sets a benchmark for the status of software size measures for software change and highlights related problems to suggest further research topics. © 2024 Copyright for this paper by its authors
Discussion on the Causes of the Observed Damages in the 2023 Kahramanmaraş Earthquakes
No full textThe devastating earthquakes in February 2023 in south-east Türkiye demonstrated that the Turkish built environment does not meet the needed performance. The frequency of earthquakes in Türkiye calls for urgent organization to upgrade the existing structures and avoid the repetition of deficient applications. Hence, it is necessary to identify the causes of the damage. The presented study concentrated on a subset of the existing inventory built under the governance of 1998 and later Turkish Earthquake Codes. Following the earthquakes in Kahramanmaraş, Türkiye, a reconnaissance study was conducted to understand the causes of the damage incurred. The extensive study covered all the major city and town centers, specifically concentrating on the 2- to 16-story reinforced concrete buildings. The first impression of the data gathered indicates significant detailing imperfections. Poor drift control, inferior layout preferences, and non-structural detailing issues are the other suspects. The observed damage and the current seismic regulation requirements will be critically discussed to form a basis for possible future improvements to the seismic code. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024