Mühendislik ve Mimarlık Fakültesi Koleksiyonu

Bu koleksiyon için kalıcı URI

https://hdl.handle.net/20.500.14704/16

Listeleniyor 1 - 20 / 101

The role of masonry infills on the interstory drift demand of reinforced concrete frames
(Elsevier Sci Ltd, 2024) Etemadi, Ali; Balkaya, Can
Most frame buildings, especially those with shear -type moment resistance frames, are affected by masonry infill panels, which change the mechanical properties of whole systems in a big way. In turn, seismic performance varies depending on the infill panel and frame interactions. In conventional structural design practice, such interaction has been overlooked. This study looks at the range of local displacement demands in shear -type frames with and without infill panels. Generic frames are developed by tuning the story stiffness and mass to produce a reasonable period range between 0.2 and 2.0 s. The masonry infill panels are simulated through equivalent diagonal struts. A Bouc-Wen-based hysteretic model is applied to incorporate the post -yielding hysteresis degradations of both columns and masonry panels. The hysteresis loop control parameter values are also given for incorporating masonry infill properties. The correlation analysis between the strength and stiffness of RC frames and masonry infills is supplied as an instrument for calibrating the hysteretic model. In the collection of records, there are a lot of near -fault ground motions, which puts a lot of seismic demands on the buildings. The modification factors via regression analysis are proposed using over 1254 nonlinear response history analyses. This modification factor is figured out by looking at the difference between the mean drift spectrum for a set of generic frames that are both bare and filled. The nonlinear analysis shows that residual drift demands can be reduced in the case of panel effects that exist for masonry-infilled mid -rise RC shear -type frames.
Evaluation of extractability of 2,4,6-trinitrophenol by secondary amine extractant in alcohols: Equilibrium and molecular dynamic study
(Elsevier, 2017) Uslu, Hasan
Extractive separation of 2,4,6-trinitrophenol (picric acid, PAH) from its aqueous solutions was examined at constant temperature of 298.2 K. The experiments were studied on the extraction of PAH (0.061 mol kg(-1)) by Amberlite LA2, a secondary amine diluted in five different alcohols such as isopropyl alcohol, isoamyl alcohol, hexanol, heptanol, and decanol. In addition to reactive extraction, experiments on physical extraction were also performed by pure diluents. Experimental results obtained from batch extraction were evaluated in terms of distribution coefficients (K-D), extraction efficiency (E), and loading factors (Z). The highest synergistic effect was achieved with isopropyl alcohol in LA-2 at a concentration of 0.588 mol kg(-1) as 98.36%. The highest value of probable equilibrium constants for the complex between acid and amine (1:1), K-11 was calculated to be 11.62 for isopropyl alcohol at 0.588 mol kg(-1) LA-2 concentration. Kinetic and potential energies of components during reactive extraction in the organic phase have been determined by molecular dynamic modeling for picric acid + isopropyl alcohol + secondary amine. The values of energy, per atom, for mixture picric acid + isopropyl + secondary amine were respectively: similar to 30,000 kcal/mol, similar to 15,000 kcal/mol, similar to-50,000 kcal/mol and similar to-60,000 kcal/mol. (C) 2016 Elsevier B.V. All rights reserved.
Constitutive Model and Mechanical Properties of Grade 8.8 and 10.9 High-Strength Bolts at Elevated Temperatures
(Asce-Amer Soc Civil Engineers, 2024) Saglik, Huseyin; Etemadi, Ali; Chen, Airong; Ma, Rujin
This paper presents an experimental study on the determination of the mechanical behaviors of Grade 8.8 and 10.9 high-strength bolts at elevated temperatures. Strength reduction coefficients are obtained based on test results at temperatures ranging from 20 degrees C to 900 degrees C, for both yield and ultimate stresses. Simplified expressions are presented to identify the strength reduction factors at considered temperatures. At 400 degrees C, the yield and ultimate strengths of bolts decrease by 30%-35% for both grades compared to those in ambient temperature. Yield strengths are 30% and 20% of yield strengths of Grade 8.8 and 10.9 bolts at ambient temperature, respectively, when the temperature exceeds 500 degrees C. The ultimate strength decreases slightly slower than the yield strength at high temperatures. Although the decrease in ultimate strength follows the decrease in yield strength at elevated temperatures, it is slightly slower. About 3%-6% of yield and ultimate strengths at ambient temperature remain for both grades at 700 degrees C. Moreover, a series of expressions are provided to obtain the full range stress-strain curve of high-strength bolts at elevated temperatures. Comprehensive literature studies are taken into consideration to propose a more generalized description of the stress-strain curves. The proposed model can be fully drawn by only using elastic modulus, yield, and ultimate stresses at ambient temperature. It is shown that the proposed model has enough efficiency to describe the general material behavior at elevated temperatures.
Adsorption Studies of Lactic Acid by Polymeric Adsorbent Amberlite XAD-7: Equilibrium and Kinetics
(Amer Chemical Soc, 2017) Uslu, Hasan; Majumder, Subhajit
The present study deals with the separation of lactic acid (LA) by a polymeric adsorbent Amberlite XAD-7. Equilibrium and kinetic studies were carried out to investigate adsorption of LA on Amberlite XAD-7 at three different temperatures (298, 308, and 318 K). Equilibrium studies revealed the optimum dose of Amberlite XAD-7 as 2.5 g. The adsorption equilibrium time was determined as 90 min. Adsorption isotherms such as Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich were validated using the obtained experimental data. Langmuir isotherms showed better fitting with the experimental data with R-2 = 0.99. Pseudo-second-order model and Elovich model were used to fit the adsorption system. Study also revealed 99% removal of LA using Amberlite XAD-7.
Extraction of Citric Acid and Maleic Acid from Their Aqueous Solutions Using a Phosphorus-Bonded Extractant, Tri-&ITn&IT-octylphosphineoxide, and a Secondary Amine, Dioctylamine
(Amer Chemical Soc, 2018) Hasret, Erdem; Kirbaslar, Sah Ismail; Uslu, Hasan
The aim of this study is to investigate the extraction of citric acid and maleic acid from their aqueous solutions using different solvent-extractant mixtures in order to find the most effective composition for the extraction. Citric and maleic acids are chosen as the carboxylic acids due to their commercial worth in the industrial processes. Carboxylic acids are recovered from their aqueous solutions by reactive extraction, a promising liquid-liquid extraction technique, using trioctylphosphineoxide (TOPO), and a secondary amine called dioctylamine (DOA). TOPO has been chosen as an extractant since it has low water solubility, high stability, and it is more environmentally friendly than the amine-type extractants. For other amine extractants used in reactive extraction processes, there is a lack of study in the literature about the extraction of these acids with DOA. Extractants were dissolved in nine different solvents (butanol, decanol, octanol, isoamylalcohol, octane, decane, methylisobutylketone, and diisobutylketone) having different chemical structures. All experiments were carried out at 298.15 K. Comparisons of the results were made using, the distribution coefficient (D), loading factor (Z), and the extraction yield (%E). It has been observed that a considerable amount of citric acid and maleic acid extraction was achieved using DOA (in the range of 13.95-99.19% and 31.94-99.41% according to the diluent used for citric acid and maleic acid, respectively) compared to that achieved with TOPO (in the range of 0.81-67.12% and 16.25-89.33% according to the diluent used for citric acid and maleic acid, respectively).
Equilibrium Data on the Reactive Extraction of Picric Acid from Dilute Aqueous Solutions Using Amberlite LA-2 in Ketones
(Amer Chemical Soc, 2017) Uslu, Hasan; Marti, Mustafa Esen
The present study is on the reactive extraction of picric acid (HPc, 2,4,6-trinitrophenol) from dilute aqueous solutions by organic phases containing Amberlite LA-2 (ALA 2) as extractant dissolved in four types of ketones. The studies were performed at 298, 308, and 318 K, and the results were used to calculate the values of distribution coefficient (KD), loading factor (Z), and degree of extraction (E%). Initial HPc concentration was kept constant at 0.061 mol.kg(-1). The maximum KD was obtained as 60 using methyl ethyl ketone when initial concentrations of PA and ALA-2 were 0.061 and 0.59 mol.kg(-1), respectively. The extraction efficiency was 98.36% under these conditions. Moreover, z-values between 0.09 and 0.27 were obtained in the ranges of parameters studied. Calculated values show that 1:2 picric acid-ALA-2 complex dominates the extraction process.
Solvent Polarity Effect when Amberlite-LA2 Is Used in the Extraction of Picric Acid
(Amer Chemical Soc, 2017) Uslu, Hasan; Datta, Dipaloy; Bamufleh, Hisham S.
The separation and recovery of picric acid (0.061 mol-kg(-1)) from its aqueous solution was studied at a fixed temperature of 298 K. The extraction experiments were performed by using a secondary amine, Amberlite-LA2 (ALA2), dissolved in five different solvents such as dichloromethane (DCM), dodecanol, toluene, benzene, and dodecane. Physical extraction data were also produced by pure solvent alone. The experimental data obtained from the batch studies were analyzed by calculating the distribution coefficient (K-D), extraction efficiency (%E), and loading factor (Z). The highest synergistic effect was achieved with DCM in ALA2 at a concentration of 0.588 mol.kg(-1) as 83.61%. The equilibrium constants for the complex formation between acid and amine (1:1 and 2:1) were calculated for all the solvents applying the mass action law.
Zn2+ Ion Adsorption from Aqueous Solution Using Montmorillonite Clay Impregnated with Tri-n-octylamine
(Amer Chemical Soc, 2017) Uslu, Hasan; Datta, Dipaloy; Bamufleh, Hisham S.
Montmorillonite (Mt) clay was used to remove zinc (Zn2+) ion from the aqueous solution. This clay material was modified (Mt-TOA) by impregnating trin-octylamine (TOA), a tertiary amine. The experiments on equilibrium and kinetics were done to analyze the effect of adsorbent amount (w, 0.05 to 0.3 g for Mt, 0.01 to 0.06 g for Mt-TOA), initial Zn2+ ion concentration (C-0, 15 mg.L-1 to 35 mg.L-1), pH (1 to 9), and contact time (t, 0 to 100 min) on the efficacy of both adsorbents. With a greater amount of adsorbent, the intake capacity of Mt and Mt-TOA for Zn2+ ion removal was found to lower but there was an increase in the separation efficiency. The optimum amount of Mt and Mt-TOA was found to be 0.1 and 0.01 g, respectively. The pH of the aqueous solution could be maintained at 7 to achieve a better adsorption of Zn2+ ion. In the kinetic experiments, after 90 min, the separation efficiency of Zn2+ ion from aqueous solution reached to a value of 86.68% with Mt (0.1 g) and 84.56% with Mt-TOA (0.01 g). Modeling of the equilibrium and kinetic data were done by using the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich, and by using the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, respectively, and the best fitted model is presented.
Adsorptive Separation of Lead (Pb2+) from Aqueous Solution Using Tri-n-octylamine Supported Montmorillonite
(Amer Chemical Soc, 2017) Datta, Dipaloy; Uslu, Hasan
Divalent lead present in the water stream was removed by using adsorption techniques with montmorillonite clay (Mt) modified with tri-n-octylamine (Mt-TOA). Batch adsorption data at equilibrium were determined with different initial Pb2+ ions concentration (8, 10, 12, 14, and 16 mg.L-1) in the aqueous solution at 298 K, and these results were correlated by using three different isotherm models, for instance, the Langmuir, the Freundlich, and the Temkin. The two-parameter Langmuir model was the best fit to the equilibrium data with a coefficient (R-2) greater than 0.99. The maximum capacities for monolayer adsorption of Mt and Mt-TOA were determined to be 3.37 mg.g(-1) and 33.1 mg.g(-1), respectively, as estimated from Langmuir. Also, experimental values were generated to evaluate the influence of adsorbent amount (w, 0.05-0.3 g for Mt, 0.01-0.06 g for Mt-TOA), starting Pb2+ ion concentration (C-0,8 mg.L-1 to 16 mg.L-1), pH (between 1 and 9), and contact period (t, from 10 to 110 min) on the removal effectiveness and adsorption capability of Mt and Mt-TOA adsorbents. In respect to kinetic studies, the removal efficiency of Pb2+ ion reached to a fixed value of 81.42% with Mt (0.1 g) and 80.67% by Mt-TOA (0.01 g) next 100 and 80 min, respectively. Pseudo-first order, pseudo-second order, and intraparticle diffusion models were studied to obtain the kinetic parameters of the adsorption practice. It is observed that the rate of mass transfer of Pb2+ ions was mainly governed by the intraparticle diffusion mechanism.
Separation of Levulinic Acid Using Polymeric Resin, Amberlite IRA-67
(Amer Chemical Soc, 2019) Uslu, Hasan; Datta, Dipaloy; Santos, Dheiver; Öztürk, Muhsin
The adsorptive separation of levulinic acid (LA) from its aqueous solution was studied by using a commercial adsorbent and weakly basic anion exchange resin, Amberlite IRA-67 (IRA-67). The data were generated for equilibrium and kinetic studies, and to analyze the performance of IRA-67 on the removal efficiency. The equilibrium study was performed to see the effect of adsorbent quantity (0.25-1.5 g) and initial LA concentrations (2-4 g.L-1) at three different temperatures (298, 308, and 318 K). To determine the kinetics of adsorption process, concentration profile was achieved up to a time of 90 min at 298 K. It was observed that both the intake capacity (32-64 mg.g(-1)) and removal efficiency (6.75-72.5%) of IRA-67 were increased with an increase in the quantity of adsorbent (0.25-1.5 g) at 298 K. From the kinetics of adsorption, 50 min was considered as an equilibrium time. Different isotherm and kinetic models were used to determine the equilibrium and kinetic parameters of LA adsorption process. From the temperature study (298, 308, and 318 K), the thermodynamic properties were also estimated at three different LA concentrations.
Adsorption of levulinic acid from aqueous solution by Amberlite XAD-4
(Elsevier Science Bv, 2017) Datta, Dipaloy; Uslu, Hasan
Levulinic acid (LA) from aqueous solutions was removed by using commercial adsorbent Amberlite XAD-4 (XAD-4). The equilibrium and kinetic studies were performed to investigate the effect of adsorbent amount (1 g to 3.5 g at 298 K, 308 K and 318 K), initial acid concentration (2 g.L-1 to 4 g.L-1 at 298 K, 308 K and 318 K), and contact time (t, 10 min to 90 min at 298 K) on the capability of XAD-4. The uptake capability and removal efficiency of XAD-4 for the adsorption of LA was observed to increase by increasing amount of adsorbent. In the equilibrium experiments of LA adsorption, adsorption capacity value was increased to 26.85 mg.g(-1) from 10 mg.g(-1) at 298 K with an increase in the amount of XAD-4. In the kinetic studies, the equilibrium time of 70 min was obtained. Also equilibrium study was performed at three different temperatures, 298, 308 and 318 K. The maximum removal was obtained at 298 K. Thermodynamic model parameters such as Delta G degrees, Delta H degrees and Delta S degrees are estimated at three different LA concentration (2 g.L-1, 3 g.L-1 and 4 g.L-1). Different isotherm and kinetic models were applied to estimate the equilibrium and kinetic parameters. (C) 2017 Elsevier B.V. All rights reserved.
Influence of fluorinated extractant aggregation in diluent on extraction of salicylic acid: Evidence from equilibrium, SAXS and molecular dynamics simulation
(Elsevier Science Inc, 2018) Wu, Xue; Chang, Zhidong; Feng, Jingge; Dang, Hui; Uslu, Hasan; Li, Wenjun
In order to get optimal extraction performance as well as ultra-low solvent residual, the extraction behavior of tris(2,2,3,3,4,4,4-heptafluorobutyl) phosphate (FTBP) dissolved in 2,3,4,5,6-Pentafluorotoluene (FB) was evaluated to investigate the influence of the aggregation state on the extraction of salicylic acid (SA). The effect of SA distribution and water content on aggregation structure in organic phase was assessed through analysis of SAXS data. Based on molecular dynamic simulation, FTBP tended to aggregate with the existence of FB to accommdate more SA molcules. Water in this case was not the critical factor for aggregation formation due to the hydrophobicity of fluorinated solvents. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Separation of copper ion (Cu2+) from aqueous solution using tri n butyl phosphate and di 2 ethylhexyl phosphoric acid as extractants
(Elsevier Science Bv, 2018) Ghosh, Amritendu; Datta, Dipaloy; Uslu, Hasan; Bamufleh, Hisham S.; Kumar, Sushil
In this study, separation of copper ion (Cu2+) from aqueous solution using two phosphorous based extractants (tri n butyl phosphate and di 2 ethylhexyl phosphoric acid) was aimed. The parameters monitored under the equilibrium study were initial copper concentration, extractant concentration, and pH. The copper concentration was taken in the range of 20 to 100 ppm, the extractant composition in the organic phase was varied from 10 to 40 vol% dissolving in toluene as an inactive diluent, and the pH effect was studied in the range of 1 to 11. The distribution coefficients were calculated, and a model equation was developed to estimate model parameters like the number of reacting molecules of the extractant and equilibrium constant using experimental results. In the kinetic study, the initial aqueous phase copper concentration, and the extractant concentration were changed, and initial rates of extraction were found out to develop a kinetic model and their parameters like rate constant and order of reaction. (C) 2018 Elsevier B.V. All rights reserved.
Enhancement of eye socket recognition performance using inverse histogram fusion images and the Gabor transform
(Wiley, 2025) Shehu, Harisu Abdullahi; Ince, Ibrahim Furkan; Bulut, Faruk
The eye socket is a cavity in the skull that encloses the eyeball and its surrounding muscles. It has unique shapes in individuals. This study proposes a new recognition method that relies on the eye socket shape and region. This method involves the utilization of an inverse histogram fusion image to generate Gabor features from the identified eye socket regions. These Gabor features are subsequently transformed into Gabor images and employed for recognition by utilizing both traditional methods and deep-learning models. Four distinct benchmark datasets (Flickr30, BioID, Masked AT & T, and CK+) were used to evaluate the method's performance. These datasets encompass a range of perspectives, including variations in eye shape, covering, and angles. Experimental results and comparative studies indicate that the proposed method achieved a significantly (p<0.001) higher accuracy (average value greater than 92.18%) than that of the relevant identity recognition method and state-of-the-art deep networks (average value less than 78%). We conclude that this improved generalization has significant implications for advancing the methodologies employed for identity recognition.
Prigogine-Flory-Patterson evaluation of systems with ionic liquids plus water or methanol: A study of specific interactions
(Elsevier, 2018) Santos, Dheiver; Bamufleh, Hisham S.; Uslu, Hasan
Descriptions of the assets of combinations of ionic liquids and polar compounds are very important for engineering projects. In this study, the modeling of binary systems involving different cations and anions was performed to observe the structural influence and the level of interaction with water and alcohol. The Prigogine-Flory-Patterson equation of state makes possible the evaluation of the level of interaction of the mixture through the Flory interaction contribution. The contribution through the characteristic pressure was shown to be of little relevance compared to the contributions of free volume and characteristic pressure. The binary mixtures, for the most part, showed a negative value, which demonstrates the strong interactions between ionic liquids and the studied compounds. (C) 2018 Elsevier B.V. All rights reserved.
Synergistic effect of fluorinated hexane as diluent of fluorinated octanol for salicylic acid extraction
(Elsevier Science Inc, 2018) Wu, Xue; Chang, Zhidong; Yuan, Junchao; Feng, Jingge; Uslu, Hasan; Li, Wenjun
In order to get optimal extraction performance as well as ultra-low solvent residual, three fluorinated hexane, perfluorohexane (C6F14), 1H-perfluorohexane (C6F13H) and 1H,6H-perfluorohexane (C6F12H2), were evaluated as diluents for synergistic effect on extraction capability of 1H,1H,2H,2H-Perfluorooctan-1-ol by the way of experimental and computational investigation. Based on extraction experiments, C6F14 showed obvious antagonistic effect because of hydrophobic nature, while the synergistic effect of C6F12H2 was better than that of C6F13H. According to DFT calculation, supported by FT-IR and H-1 NMR spectra, the synergistic effect was illustrated as that fluorinated hexane could interact with salicylic acid-fluorinated octanol complex through hydrogen bond. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Meeting the electricity demand for the heating of greenhouses with hydrogen: Solar photovoltaic-hydrogen-heat pump system application in Turkey
(Pergamon-Elsevier Science Ltd, 2023) Ozcelep, Yasin; Bekdas, Gebrail; Apak, Sudi
Providing the heating system with coal in greenhouses causes harmful results in terms of carbon emissions. In this study, analyzes were performed to meet the electrical energy required for the heating system with a heat pump from a solar photovoltaic-hydrogen system. For floor area 25000 m2 where greenhouses the required energy is obtained directly from hydrogen without using a heat pump 3000 m2 solar panel area required. The use of a heat pump reduces energy needs but it is also not feasible for large greenhouses. For convenience, a solar photovoltaic-hydrogen-heat pump system analysis was also made for 1000 m2 floor area greenhouses and it is found that the 24 m2 solar panel area is adequate in terms of meeting energy demand. Using a solar-hydrogen-heat pump system reduces carbon emissions by 86.5 tons per 1000 m2 floor area greenhouse. Considering the hydrogen storage system becomes unfeasible. We normalized the greenhouse floor area to 1 m2 and proposed reference values for hydrogen to be produced in 1 h, storage, and PV area. In addition, an analysis was made for the use of hydrogen energy for greenhouses that do not require a heating system and only work with a water pump. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Determination of Hybrid Renewable Energy Systems for Project Type Public Library Building
(Int Journal Renewable Energy Research, 2019) Altay, Ahmet; Dursun, Bahtiyar
In this context, the most convenient hybrid renewable energy system (HRES) option for the public libraries, which give services in the project type service buildings within the General Directorate of Culture and Tourism Ministry, will be chosen by evaluating the potentiality of renewable energy sources of region. In this way, both the usage of the most convenient energy source and the efficient usage of energy will be supplied. The public Library in Kirklareli City has been chosen as the example for the project type service building in this study. The most convenient option among HRES options is determined by evaluating the all energy sources potentiality of Kirklareli for the service building of Kirklareli City Public Library. It is calculated that the most appropriate HRES is PV/wind/battery for the library. The predicted total project cost of HRES is estimated to be 119,492$ and unit energy cost is determined as 2.01$/kWh for the library.
ESTIMATION OF OCCUPANCY STATUS AND LEVELS FOR INDOOR SPACES
(Scibulcom Ltd, 2020) Isikdag, U.; Apak, Sudi
Building energy use today accounts for over 40% of total primary energy consumption. The energy demand for buildings can be decreased through efficient building and facility management. The knowledge related to the use of indoor spaces is a key to successful management. The research aimed to investigate whether the occupancy levels of an indoor space can automatically be determined via machine learning algorithms based on data acquired from multiple indoor sensors. The study involved indoor data collection and a machine learning experiment. The results indicated that machine learning can be considered as a promising approach for the detection of indoor occupancy status and levels.
CLASSIFICATION OF HAZE IN CITY IMAGES WITH CONVOLUTIONAL NEURAL NETWORKS AND TRANSFER LEARNING
(Scibulcom Ltd, 2021) Isikdag, U.; Apak, Sudi
Air quality has an enormous impact on health. To take preventive measures on time, it is important to track and estimate air pollution. In the estimation of air pollution, the data acquisition from images is easy and of low-cost, when compared with sensor-based data acquisition. Machine and Deep Learning methods utilise images and videos from city cameras or social media and provide accurate estimations of air pollution. In this context, the aim of this study was testing the accuracy and efficiency of Deep Learning and Convolutional Neural Networks (CNNs) in differentiating between fog and polluted air (smog) in city images through transfer learning. The results demonstrated that Convolutional Neural Networks (CNNs) and Transfer Learning can be used as efficient methods for fog/smog classification.

Güncel Gönderiler