IYTE GCRIS Database (Izmir Institute of Technology)
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Synthesis of Carbon-Based Flexible Temperature-Controlled Semiconductive Composites
No full textGünümüzde, yarı iletken polimer matrisli kompozitler ve kullanım alanları araştırmacıların ilgisini çekmektedir. Ayarlanabilir sıcaklık profillerine sahip yarı iletken esnek polimer matrisli kompozitler, robotik, havacılık ve enerji sektörlerinde kullanım alanı bulmaktadır. Ancak karbon nanotüpler, grafen veya metal nanopartiküller gibi pahalı iletken fazlarlara duyulan ihtiyaç nedeniyle üretim maliyeti yüksektir. Bu çalışma, bu tür kompozitlerin üretimi için polidimetilsiloksan matrisinde karbon siyahı ve doğal grafit gibi ucuz iletken malzemelerin kullanılmasını amaçlamaktadır. Kompozitler 'Çözelti karıştırma' yöntemiyle (%10 ila %35 metanolde) hazırlandı ve dağılabilirlik, elektriksel iletkenlik, termal tepki ve mekanik ve morfolojik özellikler açısından test edildi. Bu substratların yüzeylerinin ıslanmayan, düşük enerjili yüzeyler (Fowke teorisine göre 26 J/m2) olduğu bulundu; bu nedenle parçacıklar daha yüksek konsantrasyonlarda (>%30) topaklanma eğilimliydiler. Aglomerasyonun olumsuz sonuçlarını ortadan kaldırmak için yüzey aktif madde ilavesi kullanıldı. Karbon içeriğinin ayarlanması iletkenliği 0 ile 10,79 S/m arasında modüle edilmesini sağlamıştır. 3,17 S/m iletkenliğe sahip tipik bir kompozit, 30 V yük altında 49,7°C yüzey sıcaklığı göstermiştir. PDMS ile karşılaştırıldığında kompozitlerin mekanik özellikler olumluydu; optimum iletkenliğe ve sıcaklık tepkisine sahip bir kompozit, çekme mukavemetinde %50'lik bir düşüşe rağmen elastik modülde %97,8 ve yırtılma mukavemetinde %197 artış gösterdi. Çalışma, istenen sıcaklık profillerine sahip yarı iletken esnek kompozitlerin üretiminde önemli ekonomik potansiyelin altını çiziyor.Semiconducting flexible polymer matrix composites with tunable temperature profiles find use in consumer goods, robotics, aerospace, and energy sectors. However, the manufacturing cost is high due to the need for expensive conductive phases, such as carbon nanotubes, graphene, or metal nanoparticles. This study aims to use inexpensive conductive materials, such as carbon blacks and natural graphite in polydimethylsiloxane matrix to manufacture such composites. The composite samples prepared by the solution-mixing approach were tested for dispersibility, electrical conductivity, thermal responsiveness, and mechanical and morphological characteristics. They displayed non-wettable and low-energy surfaces (26 J/m²) and, hence, were prone to agglomeration at high carbon contents (>30%). Surfactant addition was employed to counteract the negative consequences of agglomeration. Adjusting the carbon content could modulate conductivity between 0 and 10.79 S/m. A typical composite with 3.17 S/m conductivity showed a surface temperature of 49.7°C under a load of 30 V. Compared to bare PDMS, mechanical properties were favorable; a composite with optimal conductivity and temperature response showed increases of 97.8% in elastic modulus and 197% in tear strength, despite a 50% decrease in tensile strength. The study highlights significant economic potential in manufacturing semiconductive flexible composites with desired temperature profiles
Modelling and Analysis of Heat Pump Integrated Photovoltaics-Wind Systems for an Agricultural Greenhouse in Turkey
No full textThis study focused on modelling and analysing photovoltaics and wind systems to meet the heating demand of a commercial greenhouse. The aim is to evaluate technical, economic, and environmental performances of the related systems and to determine the optimum configuration. A novel approach was introduced by integrating hybrid energy systems with large-scale wind turbines and developing a dynamic heat transfer model. A large commercial greenhouse with an area of 26,640 m2 located in Izmir, Turkey was selected for considering Mediterranean climate, and a detailed heat transfer model of the greenhouse were developed considering heat transfers by convection, radiation, ventilation, and infiltration. A combination of air source heat pumps, photovoltaic panels and wind turbines were used for meeting the heating demand of the related greenhouse. Five different on-grid energy systems scenarios, namely (i) Photovoltaics-Heat Pump, (ii) Photovoltaics-Wind Turbine- Heat Pump, (iii) Wind Turbine- Photovoltaics- Heat Pump (iv) Wind Turbine- Heat Pump, and (v) only Heat Pump were considered. The system modelling with a detailed heat transfer analysis of the greenhouse was made by MATLAB. The energy analysis of the systems was performed on an hourly basis for one calendar year. The annual heating demand and the corresponding electricity consumption of the greenhouse were calculated as 497.37 and 114.07 kWh/m2, respectively. Net Present Value, Levelized Cost of Energy and CO2 savings were used to evaluate economic and environmental performances of the systems. Among five on-grid energy system scenarios, the first scenario, consisting of 5271 photovoltaic panels and 20 heat pumps, emerged as the most economically attractive choice with Net Present Value and Levelized Cost of Energy of /kWh, respectively. Critical parameters affecting the economy of this scenario were found to be electricity prices, tomato yield, and photovoltaic panel prices. For environmental evaluation the fourth scenario, integrating wind turbines and heat pumps, achieves the highest CO2 savings of 2,064.73 tons due to increased renewable electricity production and lower life-cycle CO2 emissions of wind turbines compared to photovoltaic systems. This analysis enhanced the understanding of energy dynamics in greenhouse environments, contributing to the advancement of sustainable practices in agriculture. © 2024 Elsevier Lt
Design Discourse in Discount Shopping Context: Textual Analysis With Critical Studies Perspective and Deconstructionist Theory
No full textIn consumption culture, individuals need things to update their selves or to repre-sent their identities. The more they update their belongings, the more they feel unsatisfied. In this cultural recycling, everyday objects become objects of desire, while the notion of design functions to create attraction. The problem originates in the disengagement of subjects–objects in which the capitalist economic system gets benefits sustaining the cycle of mass production-consumption. To get more benefit, this cycle is sped up along with discount shopping context. The study aims to produce a design discourse in discount shopping context in relevance of the issues of individuality and ethics. The method is a textual analysis with critical studies perspective and deconstructionist approach. The texts are the questionnaire transcripts written by fifteen women. Critical studies perspective clarifies power relations between capitalist economic system and consumer; and deconstructivist approach determines binary relations in relevance of individuality, and ethics and heterogeneity of the texts concerning to design. Along with these two approaches, textual analysis creates a discursive structure. The structure is used to generate a design discourse in which the meaning of design is situated. In this structure, design would be something in a specific heterogeneity and relations around the matters of individuality and ethics. The discursive structure is of importance that summarizes the method used and determines all coherencies around the definitions of design. This structure also could be a useful source for the production of other critical discourses on the relations of subjects–objects and the position of design in consumption culture. © 2023 Intellect Ltd Article
Efficiency Evaluation of Single and Double Tuned Mass Dampers on Building Response Reduction by Considering Soil-Structure Interaction
No full textTuned mass dampers (TMDs) and multiple tuned mass dampers (MTMDs) are among the simplest, most reliable, and most frequently employed structural control devices. The efficiency of TMDs and MTMDs depends on their parameters, including the mass, frequency ratio, and damping ratio. Several analytical and metaheuristic methods have been proposed for the optimal design of tuned mass dampers. The aims of this study are: (1) to investigate the differences in efficiency between a number of TMD design methods and (2) to evaluate the differences in efficiency between a single TMD and double TMD (DTMD) in reducing the seismic response of structures by considering soil-structure interactions (SSI). In the first numerical study, the effectiveness of TMDs optimized using seven analytical methods, and TMD and DTMD optimized using a metaheuristics algorithm called Mouth Brooding Fish (MBF) in reducing the response of a fifteen-story structure under 22 far-field and 14 near-field earthquakes is compared. In the second example, in addition to the seven analytical-based designed TMDs, and MBF-based TMDs and DTMDs, the Jaya algorithm based, and plasma generation optimization-based designed TMDs are used, and the same procedure is applied to a forty-story structure. The results show that there is no important difference among these methods, which may indicate that the uppermost optimization level for a regular TMD has been reached. Furthermore, the results indicate that the TMD and DTMD are almost equally effective at reducing the seismic response of structures when the SSI effect is taken into consideration. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024
Integrating Experimental and Machine Learning Approaches for Predictive Analysis of Photocatalytic Hydrogen Evolution Using Cu/G-c3n4
No full textThis study addresses environmental issues like global warming and wastewater generation by exploring waste-toenergy strategies that produce renewable hydrogen and treat wastewater simultaneously. Cu/g-C3N4 is used to evolve hydrogen from sucrose solution and the impact of reaction parameters such as pH (3, 5, and 7), Cu loading (5, 10, and 15 wt%), catalyst amount (0.1, 0.2, and 0.3 g/L), and oxidant (H2O2) concentration (0, 10, and 20 mM) on the evolved hydrogen amount is examined. Characterization study confirmed successful incorporation of Cu without significantly altering g-C3N4 properties. The highest hydrogen production (1979.25 mu mol g- 1 ; sdot;h- 1) is achieved with 0.3 g/L catalyst, 20 mM H2O2, 5 % Cu loading, and pH 3. The experimental study concludes that Cu/g-C3N4 is an effective photocatalyst for renewable hydrogen production. In addition to the experimental investigations, various machine learning (ML) models, including Random Forest, Decision Tree, XGBoost, among others, are employed to analyze the impact of reaction parameters and forecast the quantities of produced hydrogen. Alongside these individual models, an ensemble approach is proposed and utilized. The R2 values of these ML models ranged from 0.9454 to 0.9955, indicating strong predictive performance across the board. Additionally, these models exhibited low error rates, further confirming their reliability in predicting hydrogen evolution
Small Angle X-Ray Scattering Analysis of Thermophilic Cytochrome P450 Cyp119 and the Effects of the N-Terminal Histidine Tag
No full textCombining size exclusion chromatography-small angle X-ray scattering (SEC-SAXS) and molecular dynamics (MD) analysis is a promising approach to investigate protein behavior in solution, particularly for understanding conformational changes due to substrate binding in cytochrome P450s (CYPs). This study investigates conformational changes in CYP119, a thermophilic CYP from Sulfolobus acidocaldarius that exhibits structural flexibility similar to mammalian CYPs. Although the crystal structure of ligand-free (open state) and ligand-bound (closed state) forms of CYP119 is known, the overall structure of the enzyme in solution has not been explored until now. It was found that theoretical scattering profiles from the crystal structures of CYP119 did not align with the SAXS data, but conformers from MD simulations, particularly starting from the open state (46 % of all frames), agreed well. Interestingly, a small percentage of closed-state conformers also fit the data (9 %), suggesting ligand-free CYP119 samples ligand-bound conformations. Ab initio SAXS models for N-His tagged CYP119 revealed a tail-like unfolded structure impacting protein flexibility, which was confirmed by in silico modeling. SEC-SAXS analysis of N-His CYP119 indicated pentameric structures in addition to monomers in solution, affecting the stability and activity of the enzyme. This study adds insights into the conformational dynamics of CYP119 in solution. © 2024 Elsevier B.V
A Smart Building Energy Management Incorporating Clustering-Based Tariffs in the Presence of Domestic Solar Energy, Battery, and Electric Vehicle
No full textSmart buildings play a crucial role in optimizing energy management within the power network. As end-users of the power network, they have the ability to not only reduce economic costs for householders but also modify the technical indices of the power network. To promote efficient device management in smart homes (SH), demand response programs are recommended for consumers. This research investigates the application of clusteringbased electricity pricing strategy aimed at effectively managing the energy devices of a residential smart home. The utilized method categorizes the electricity tariff into five rates according to the clustering of the realtime pricing program. Ward's clustering method is utilized to cluster and determine new electricity tariffs. The primary goal of the energy management program is to minimize the building's energy cost, which is accomplished through the utilization of the multi-verse optimizer. The smart home consists of essential and manageable appliances, a photovoltaic panel (PV), a sodium-sulfur (NaS) battery, and an electric vehicle (EV). The initial parameters of the PV and EV are modeled stochastically by their probability distribution functions and calculated using the Latin hypercube sampling algorithm. The smart building's performance is assessed by taking into account various demand response programs. The numerical results present that the application of the clusteringbased management method has resulted in a significant reduction of 23-43 % in the electricity cost of smart homes. Additionally, the smart home exhibits a more linear consumption pattern when considering the electricity tariffs based on the clustering approach
Calcite Precipitation on Excavated Andesite Surfaces From the Archaeological Sites of Aigai and Assos (turkey)
No full textThe conservation interventions of crusts or patinas formed on the surfaces of stone monuments should be evaluated within a comprehensive approach in archaeological excavations, taking into account their material characteristics. In this study, the mineralogical, chemical and microstructural characteristics of whitish crusts formed on the surfaces of buried and later excavated andesite surfaces at the archaeological sites of Aigai and Assos (Turkey) were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence (XRF) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) analyses in order to establish a conservation approach at the archaeological sites. The whitish crusts formed on the excavated andesite surfaces are mainly composed of calcite with freshwater diatom species. Calcite is most likely formed by the alteration of plagioclase by carbon dioxide in the soil during the burial of the andesites. In the soil, CO2 reacts with plagioclase to produce kaolinite and calcite which are precipitated on the andesite surfaces after excavation. The presence of freshwater diatom species in the whitish crusts may indicate that the andesite remains were buried in the waterlogged soil for many years and later excavated. Therefore, whitish crusts should not be cleaned from the andesite surfaces, as they are a sign of the burial history of the monuments and a protective layer against weathering
Gpprmon: Gpu Runtime Memory Performance and Power Monitoring Tool
No full textGraphics Processing Units (GPUs) perform highly efficient parallel execution for high-performance computation and embedded system domains. While performance concerns drive the main optimization efforts, power issues become important for energy-efficient GPU executions. While performance profilers and architectural simulators offer statistics about the target execution, they either present only performance metrics in a coarse kernel function level or lack visualization support that enables performance bottleneck analysis or performance-power consumption comparison. Evaluating both performance and power consumption dynamically at runtime and across GPU memory components enables a comprehensive tradeoff analysis for GPU architects and software developers. This paper presents a novel memory performance and power monitoring tool for GPU programs, GPPRMon, which performs a systematic metric collection and offers useful visualization views to track power and performance optimizations. Our simulation-based framework dynamically collects microarchitectural metrics by monitoring individual instructions and reports achieved performance and power consumption information at runtime. Our visualization interface presents spatial and temporal views of the execution. While the first demonstrates the performance and power metrics across GPU memory components, the latter shows the corresponding information at the instruction granularity in a timeline. Our case study reveals the potential usages of our tool in bottleneck identification and power consumption for a memory-intensive graph workload. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024
Rna Msup>6/Sup>a Methylation at the Juxtaposition of Apoptosis and Rna Therapeutics
No full textTargeting RNA m(6)A marks in apoptosis-related transcripts holds promise for RNA therapeutics. However, pathway-specific RNA m(6)A sites on pro- or antiapoptotic transcripts have not been fully unveiled, let alone characterized. This article summarizes the current knowledge and gaps in the cellular response modulated by apoptotic stimulus-specific RNA m(6)A marks