Yazarlar
- Tozlu, Alperen(13)
- Ergün, Mustafa(11)
- Artar, Musa(10)
- Cuce, Erdem(9)
- Cuce, Pinar Mert(8)
- Yurdakul, Muhammet(8)
- Imamoglu, Ilyas Kays(7)
- Esmer, Yusuf(6)
- Isik, Cem(6)
- Ongan, Serdar(6)
- Can, Ömer(5)
- Guclu, Tamer(5)
- Kahveci, Hakan(5)
- Tayfur, Bilal(5)
- Yilmaz, Fatih(5)
- Ates, Sevket(4)
- Guler, Evrim(4)
- Gökçe, H.S.(4)
- Karakus, Murat(4)
- Tapkın, Serkan(4)
- Tercan, Emre(4)
- Çaglar, Hakan(4)
- Özahi, Emrah(4)
- Abdioglu, Murat(3)
- Abusoglu, Aysegul(3)
- Altuntas, Serkan(3)
- Ateş, Şevket(3)
- Ayberkin, Doruk(3)
- Aydin, Rahman(3)
- Cakici, Ziya(3)
- Cakir, Mehmet(3)
- Carbas, Serdar(3)
- Dereli, Turkay(3)
- Engin, Mustafa Alptekin(3)
- Gökçe, H. Süleyman(3)
- Güngör, Okan(3)
- Kiral, Adnan(3)
- Kuziboev, Bekhzod(3)
- Murat, Yetis Sazi(3)
- Okur, Fatih Yesevi(3)
Yayınlar
- MakaleAçık Erişim2022Scopus SJRQ1Techno-economic assessment of a synthetic fuel production facility by hydrogenation of CO2 captured from biogas
Tozlu, Alperen
In this study, a thermodynamic and economic analysis of a synthetic fuel production facility by utilizing the hydrogenation of CO2 captured from biogas is carried out. It is aimed to produce methanol, a synthetic fuel by hydrogenation of carbon dioxide. A PEM electrolyzer driven by grid-tie solar PV modules is used to supply the hydrogen need of methanol. The CO2 is captured from biogas produced in an actual wastewater treatment plant by a water washing unit which is a method of biogas purification. The required power which is generated by PV panels, in order to produce methanol, is found to be 2923 kW. Herein, the electricity consumption of 2875 kW, which is the main part of the total electricity generation, belongs to the PEM system. As a result of the study, the daily methanol production is found to be as 1674 kg. The electricity, hydrogen and methanol production costs are found to be $ 0.043 kWh−1, $ 3.156 kg−1, and $ 0.693 kg−1, respectively. Solar availability, methanol yield from the reactor, and PEM overpotentials are significant factors effecting the product cost. The results of the study presents feasible methanol production costs with reasonable investment requirements. Moreover, the efficiency of the cogeneration plant could be increased via enriching the biogas while emissions are reduced.
AtıfScopus34WoS32OpenAlex37
İncele - BildiriYalnız künye2022SpectrumChain: An Efficient Spectrum Management Framework in Blockchain-Enabled Flexible SDONs
Guler, Evrim; Karakus, Murat; Uludag, Suleyman
Huge potentials of optical networks provide an excellent choice in meeting the exponential growth in bandwidth demand. In particular, Elastic Optical Networks (EONs), with its promising potentials in increased availability, failure resilience, load-balancing, new use cases for on-demand opportunities, and efficient resource allocations, are good candidates for the future high-speed networks. When EONs are augmented with the emerging Software Defined Networking (SDN), that decouples the data and control planes, an agile and synergistic combination emerges under a general term of SDN-based optical networking (SDON), albeit with operational challenges. In this paper, we introduce a blockchain-enabled QoS-based inter-Internet Service Provider (ISP) routing coordination framework for SDONs, SpectrumChain (SC), to eliminate centralized mediators and reduce QoS signaling overhead. Experimental results show that the SC framework can effectively handle the QoS-enabled inter-ISP routing in SDON architecture in terms of flow setup time, message overhead, and requests serviced as compared to the traditional approaches.
AtıfScopus6WoS5OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ1Improvement of mechanical and transport properties of reactive powder concrete using graphene nanoplatelet and waste glass aggregate
Arslan, S.; Öksüzer, N.; Gökçe, H.S.
In this study, the use of graphene nanoplatelet (GNP) and waste glass aggregate (WGA) was investigated to improve the mechanical and transport properties of reactive powder concrete (RPC), which is an ultra-high strength concrete type. The co-addition of 0.14% GNP and 30% WGA resulted in a significant increase in the compressive strength of RPC from 192.9 to 258.9 MPa and flexural strength from 16.2 to 38.7 MPa. In the study, the most significant improvement (138.6%) was obtained for the flexural strength values of RPC. Considering the strength aspects, the relevant amounts of GNP and WGA enable production of RPC ensuring a conducted electrical charge of less than 100 Coulombs; that is, with negligible chloride ion permeability. Accordingly, the highest improvement (59.8%) after flexural strength was found for the resistance of the specimens against chloride ion penetrability. In conclusion, the findings of this study show that eco-efficient production of RPC with superior mechanical and durability characteristics can be achieved using GNP and WGA, with lower cement consumption per unit value of these studied characteristics, reaching 59%.
AtıfScopus31WoS26OpenAlex32İncele - MakaleAçık Erişim2022Scopus SJRQ1Double adaptive power allocation strategy in electric vehicles with battery/supercapacitor hybrid energy storage system
Çorapsız, Muhammed Reşit; Kahveci, Hakan
This paper proposes a new energy management strategy (EMS) for electric vehicles (EVs) with battery/supercapacitor hybrid energy storage systems (HESS). Firstly, the battery/supercapacitor HESS configuration and obtaining the load current from the driving cycle are comprehensively explained. Secondly, fixed and adaptive frequency-based (AFB) EMS are discussed in detail. In the proposed method, the current demanded by the load is separated into low and high-frequency components with the help of an adaptive low-pass filter (A-LPF). In addition, adaptive battery current (ABC) is generated according to the supercapacitor (SC) state of charge (SoC), and a double adaptive power allocation strategy is performed. The proposed method is compared with the AFB-EMS for load currents, load powers, DC link voltages, filter cut-off frequencies, battery, and SC SoCs on the UDDS driving cycle. When the obtained results were evaluated together, it was observed that the proposed method completed the driving cycle with a higher battery SoC and realized the adaptive cut-off frequency in a narrower band.
AtıfScopus14WoS12OpenAlex14İncele - MakaleAçık Erişim2022Scopus SJRQ1Optimum sizing design of steel frame structures through maximum energy dissipation of friction dampers under seismic excitations
Artar, Musa; Carbas, Serdar
This paper focuses on optimum sizing design of steel frame structures equipped with friction dampers (FDs) in order to prevent the vulnerable effect of an earthquake. The fundamental concept is to maximize the energy dissipation of implemented FDs under different seismic excitations. The FDs utilized as passive energy dissipation devices in a steel structure increase the energy dissipation capacity of the structure by decreasing the seismic demand during an earthquake. In this context, the Pall friction dampers (PFDs) are implemented as diagonal damped brace members in investigated structures. Three different earthquake records (Kobe, Kocaeli-Duzce, Erzincan) are utilized to acquire nonlinear dynamic responses of the steel frame structures through time-history analyses. The open application programming interface (OAPI) functions are used to integrate a finite element modelling based structural analysis program, SAP2000, with a design optimization algorithm encoded in MATLAB for achieving the exact structural behaviours by synchronously data transferring. As an optimizer, one of the recent nature-inspired metaheuristic techniques, so-called Grey Wolf (GW) algorithm is used. Initially, under effect of seismic excitations, the steel frame structures are optimally sized for attaining minimum design weights without implementing the PFD elements by subjecting only strength, displacement, drift, and geometric structural design constraints taken from AISC-LRFD practice code provisions. Afterward, in order for optimally modelling the PFD elements, the frames are equipped with PFDs to calculate optimum yield strengths that is defined as slip load of a PFD. To do so, the GW algorithm ensures the maximizing of the dissipated energy and controls the yield strengths between the stories since the shear force due to the earthquake increases towards the base of the structure. Eventually, the provisions-based sizing design optimizations of the steel frame structures equipped with optimally modelled PFD elements are conducted under seismic excitations for conclusive evaluations.
AtıfScopus21WoS18OpenAlex20İncele - MakaleAçık Erişim2022Scopus SJRQ3Design of an efficient vehicle-actuated signal control logic for signalized intersections
Cakici, Ziya; Murat, Yetis Sazi; Aydin, Metin Mutlu
The effectiveness of fixed-time management systems dramatically decreases in case of fluctuating traffic demands in signalized intersection approaches. The result is the utter waste of time in traffic to be followed by material, psychological, and ecological problems. In recent years, to minimize the negative impacts of these problems, many researchers have focused on Intelligent Transportation Systems (ITS). As it is known, one of the applications of ITS is called vehicle-actuated (traffic-actuated) management systems. Because the success of these types of applications is directly related to the created control logic, the selection of the most proper control parameters for the created control logic is an important issue. This study aims to create an effective control logic and flow chart for the vehicle-actuated management system. At the end of the analyses, it is seen that the created vehicle-actuated management system can adapt to fluctuations in traffic demands in signalized intersection approaches. Average vehicle delays, fuel consumptions, and exhaust emissions can be reduced significantly by the created system. In case of fluctuations in traffic demands in intersection approaches, it is concluded that the performance of the intersection may increase enormously because of the created vehicle-actuated management system.
AtıfScopus4WoS6OpenAlex7İncele - MakaleAçık Erişim2022Scopus SJRQ2A novel internal curing method for 3D-printed geopolymer structures reinforced with a steel cable: Electro-heating
Gökçe, H.S.; Güngör, O.; Öksüzer, N.
Buildability and structural integrity are the inherent challenges of 3D printed geopolymer structures needed to be overcome. Reinforcing with steel cable ensuring a higher structural integrity of the printed structure can simultaneously improve the buildability due to the heating capability of this component. The controllable instant heating capability of steel cable was achieved by the use of a specific circuit system in the study. As a novel internal curing technique, electro-heating is recommended in the additive manufacturing of steel cable-reinforced geopolymer structures by the authors.
AtıfScopus4WoS3OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ2Assessment of waste-to-energy potential of ELT management: An actual case study for Erzincan
Güngör, Osman; Tozlu, Alperen; Arslantürk, Cihat
End-of-life tires (ELTs) and their decomposition are becoming a major environmental issue in the local region as a result of economic and technological challenges. Despite this, ELT management is gaining popularity as an advanced function for treating tires to obtain char, oil, and gas products using pyrolysis. The main goal of this article is to integrate data from an actual recycling plant with the activities of pyrolysis products and their physical properties in the literature. This article presents energy potentials and basic applications of pyrolysis products as well as advances in the current situation in ELT management in the world. Accordingly, an existing ELT management in Erzincan, Turkey is explained in detail by considering the available energy recovery and material treatment activities. In this plant, which has an installed power capacity of 12 MW, approximately 25 tons of pyrolytic oil, 10.7 tons of pyrolytic gas, 24 tons of carbon black and, 10.4 tons of steel are produced daily. The calorific values of carbon black and pyrolytic oil for the products leaving the pyrolysis plant are close to the values in the literature, which is promising. In the plant, the overall thermal efficiency of the system and the engine is found to be 26.34% and 51.24%, respectively. On the other hand, to supply additional power to the plant utilizing exhaust gas discharged to the atmosphere, some thermodynamic models can be developed; additionally, more rational values can be obtained through thermoeconomic and optimization.
AtıfScopus1WoS2OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ1Thermoeconomic analysis of a low-temperature waste-energy assisted power and hydrogen plant at off-NG grid region
Tozlu, Alperen; Kayabasi, Erhan; Ozcan, Hasan
In this study, thermoeconomic analysis of a CO2 power cycle and PEM hydrogen system using ultra-low temperature waste heat from a milk production facility is conducted. In the transcritical CO2 cycle, low-temperature LNG evaporation is used for cooling the condenser to increase the temperature difference enabling low temperature waste heat use. In addition, a PEM electrolyzer produces hydrogen to reduce the LNG requirement at the plant. A CO2-water exchanger has been designed to recover the pasteurized water's excess heat and evaporate the CO2 using Simcenter-Flomaster software. The inlet mass flow rates and outlet temperatures of the heat exchanger were optimized by performing thermoecomic analysis, and the thermal and economic performance of the facility was examined. The power cycle has 14% higher efficiency when LNG is used as the heat sink compared to ambient temperature condensation with an electricity production cost range at 0.05–0.11 $/kWh, and the hydrogen generation cost is between $2.6–5.20 kg−1. It is found that the plant could only be economically feasible when less than 50% of the power produced is used for hydrogen generation. Consequently, the proposed system can co-generate power and on-demand hydrogen in off-NG grid regions with reasonable investment and product costs.
AtıfScopus6WoS6OpenAlex8İncele - MakaleAçık Erişim2022Scopus SJRQ3IoT-TDMA: A performance evaluation of TDMA scheme for wireless sensor networks with Internet of Things
Kosunalp, Selahattin; Kaya, Yunus
This article focuses on the design and implementation of an improved version of TDMA scheme for wireless sensor networks (WSNs) exploiting the Internet of Things (IoT) phenomena. The main motivation behind this work is to create an environment for WSNs to benefit from IoT opportunities. An extensive review of the state-of-the-art medium access control (MAC) approaches proposed for IoT is carried out underlying their basic principles and features. An adaptation of TDMA strategy, called IoT-TDMA, is proposed to enhance the channel performances particularly throughput and latency. To test the performance of IoT-TDMA practically, a low-cost node hardware with the capability of Internet connection is essentially designed. IoT-TDMA has been implemented on real-world highly scalable single-hop and multi-hop topologies. Performance results indicate significant improvements in terms of channel throughput and end-to-end delay in comparison to a recently proposed efficient MAC scheme.
AtıfScopus17OpenAlex18İncele - MakaleAçık Erişim2021An Investigation of the Adaptation of Turkish Textile Enterprises to Industry 4.0
Yıldız, Aytaç; Özbek, Ahmet; Alan, Mehmet Asif
Industry 4.0 is a new understanding of production and is based (to a great extent) on the removal of people\rfrom production by radically changing the understanding of people-oriented production – a concept that has\rdominated for a long time. This understanding is becoming more widespread day by day and it is predicted\rthat the future will mean a better understanding of production. Therefore, it is anticipated that adaptation to\rthis understanding will be one of the determining factors in the future success of enterprises. In this study, it\rwas aimed to investigate the adaptation of textile companies operating in Turkey to Industry 4.0. Within the\rscope of the study, a questionnaire was prepared to analyze the perspectives of textile companies towards\rindustry 4.0 and their expectations from the industry 4.0 technologies they use. The questionnaire was\rapplied to 67 textile companies that ranked in the top 500 large enterprises of the Istanbul Chamber of\rIndustry (ISO) in 2017 and 2018 and the data obtained were analyzed. According to the results of the analysis\rit was determined that the technology that businesses use the most is ERP. Due to the high investment cost,\rit has been determined that only half of enterprises invest in industry 4.0 technologies, that they believe that\rindustry 4.0 is applicable in the textile industry, that to invest in these technologies will increase productivity\rand reduce costs, and as a result, the highest increase in efficiency will be achieved.
AtıfOpenAlex3TR Dizin2
İncele - MakaleAçık Erişim2021Improving of Lightweight Concrete Properties Produced with Pumice Aggregate of Nevşehir Region with Fly Ash Substitution
Apay, Ahmet Celal; Çaglar, Hakan; Çimen, Selçuk; Çağlar, Arzu; Kale, Mehmet Oğuzhan
In this study, it was aimed to determine the effects of industrial waste fly ash substitution on physical and mechanical properties of lightweight concrete. In this respect, lightweight concrete samples were produced by the use of fly ash as a cement replacement material in different proportions (1%, 3% and 5%). In lightweight concrete production, the Nevşehir region acidic pumice has been used as aggregate. The physical and mechanical properties of these lightweight concrete samples were investigated and microstructural analysis was carried out. To determine the physical differences, dry unit volume weight, capillary water absorption, porosity, compactness and freezethaw experiments were conducted. For the determination of mechanical properties, tensile splitting strength and compressive strength tests were applied. SEM images have been interpreted to examine the structural differences occurring within the material. As a result of the study, it was determined that the physical and mechanical properties of the ligtweight concrete were improved with the increase in the amount of fly ash. The best results were obtained from sample with 5% fly ash substitution. The use of industrial waste in a large sector such as construction, which adversely affects the ecological balance, will be an opportunity to dispose of waste.
AtıfOpenAlex7İncele - MakaleAçık Erişim2021Ürkiye’de Bilgi ve İletişim Teknolojileri (BİT), Uluslararası Göç ve Ekonomik Büyüme Arasındaki İlişki
Arı, Ari
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AtıfOpenAlex2İncele - MakaleYalnız künye2021The first telephone lines and their usage in samsun samsun during the second constitutional period
Aktaş, Esat
The telephone, one of the modern gadgets, was invented in the 19th century. There were postal systems and telegraph centres for communication before the telephone was introduced. It is seen that the centralist states developed these tools. In the 19th century, the increase in trade on the seas brought the development of the port cities, which signs a driving force behind urban modernization. Being one of these cities, Samsun developed rapidly during the century. Modern vehicles appeared in these developing cities. However, the use of the telephone was banned by the Ottoman administration at the time. Only in the early 20th century, was it permitted but restricted to residential use. After the declaration of the Constitutional Monarchy II, the government removed the ban on this issue. The telephone eventually was brought to Samsun in 1907 by the merchants. This study discusses its development during the second constitutional period regarding the Samsun case. The study deals with Samsun's communication infrastructure in terms of the telephone, examining the history of the phone in Samsun. The study reviews the arrival of the telephone in the city and how and where it was installed as a means of communication. The study also aims to determine its effect on the transformation process regarding modernization. The study used the Ottoman Archive documents about Samsun to investigate who brought the telephone first, where it was used, what the policies and practices of the central state and local investments of the authorities were. The study examines how they worked, under what conditions the lines were made, and what strategic goals were sought for the near future. The study concludes that the telephone lines were established for official and civil use in Samsun, the project was fulfilled despite difficulties, and these lines were inherited by the modern Republic.
- Derleme MakaleAçık Erişim2021Investigation of Shale Gas Reserves in The World and A Case Study for Electricity Production from Shale Gas in Turkey
Oztekin, Erman Kadir; Tozlu, Alperen
Shale gas reserves, which is globally accepted as unconventional gas resource, scattered around the world and can be used in order to meet the growing energy needs due to limited amounts of conventional resources. Since notable effort has to be put in order to investigate and drill shale gas resources the early decision has to be made carefully, especially considering the economic benefits. Several factors must be considered including the known technically recoverable shale gas amount at the selected region, current technology to drill the shale source and the amount of investment before the extraction of shale gas. In this study, global underground shale gas amount and recent discoveries as well as the potential shale gas areas in Turkey are presented. Benefits of using shale gas for electricity generation and common methods being used during shale gas extraction are studied along with gas and liquid flow mechanisms. At the end, general overview of separation and utilization of shale gas components is schematically presented. In the case study, the potential of electricity generation in the SE Anatolia region in Turkey is estimated with only using methane obtained from the shale gas purification process at the power generation step. According to the estimations, 3337.8 MW electric power may be generated for 50~55 years, at the appropriate gas engine by using 8.5 billion cubic meter shale gas annually.
- MakaleAçık Erişim2021Strategy Development for the Applicability of Photovoltaic Systems in Hospitality Enterprises using SWOT Analysis and AHP Method: The Case of Sinop Province
Alcan, Yalçın; Esmer, Yusuf; Alcan, Özlem
Strategy is the way to achieve the objective or goal. In this context, strategies are developed and attempted to be implemented in order to achieve certain objectives or goals in each enterprise or sector. In this study, by combining SWOT analysis and AHP method, a strategy was developed to use the photovoltaic systems in hospitality enterprises. For this purpose, in the study, based on the relevant literature, a research has been conducted on the applicability of photovoltaic systems in the hospitality enterprises in Sinop. In the research, SWOT analysis was carried out for managers, experts and related academicians to identify the strengths and weaknesses of photovoltaic systems and opportunities and threats to these systems. 4 strategies were developed using the data obtained from the SWOT analysis, and then the most suitable one was tried to be determined by AHP method. As a result of the research, it has been determined that the most suitable strategy for the applicability of photovoltaic systems for hospitality enterprises in Sinop province is carrying out studies for photovoltaic systems to be an alternative energy source in the tourism sector.
AtıfOpenAlex4TR Dizin2İncele - MakaleAçık Erişim2021Scopus SJRQ4Sinyalize Dönel Kavşaklarda Diferansiyel Gelişim Algoritması ile Sinyal Süre Optimizasyonu
Murat, Yetis Sazi; Cakici, Ziya
“Vakit” in “Nakit” ten daha değerli olduğunu her fırsatta dile getiren insanoğlu, günlük hayatta, zamanının büyük bir bölümünü de trafikte harcamaktadır. Özellikle sinyalizasyon sistemi ile kontrol edilen kavşaklarda meydana gelen yüksek düzeyli zaman kayıpları, yakıt tüketimleri, gürültü kirlilikleri vb. psikolojik, ekonomik ve çevresel problemleri de beraberinde getirebilmektedir. Karşılaşılabilecek olası problemler ise yalnızca doğru ve güçlü bir matematiksel altyapıya sahip olan denetim stratejileri ile en aza indirilebilmektedir. Bu çalışmada, sinyalize dönel kavşakların performanslarının arttırılması amacıyla, kavşaktaki ortalama taşıt gecikmesinin minimize edilmesini hedefleyen bir sinyal süresi optimizasyonu modeli oluşturulmuştur. Oluşturulan modelde, fazlara ait sinyal süreleri ve devre süresi Diferansiyel Gelişim Algoritması kullanılarak optimize edilmiştir. Çalışma kapsamında, modelin etkinliği, Denizli Kelleci Kardeşler Kavşağı’ndan 4 farklı zaman periyodunda toplanan gerçek trafik verileri kullanılarak VISSIM simülasyon programında test edilmiştir. Sonuç olarak, söz konusu model ile ortalama gecikmelerin, kavşaktaki mevcut duruma kıyasla yaklaşık %45’ e kadar azaltılabileceği belirlenmiştir.
AtıfOpenAlex8TR Dizin5İncele - MakaleAçık Erişim2021Clustering framework to cope with COVID-19 for cities in Turkey
Guleryuz, Didem; Ozden, Erdemalp
Introduction: This article is the product of the research Clustering Framework to Cope with COVID-19 for Cities in Turkey, developed at Bayburt University in 2021. Problem: Turkey's risk map, presented in January 2021, to take local decisions in tackling the COVID-19 pandemic, was based on confirmed cases only. Health, socio-economic and environmental indicators are also important for management decisions of COVID-19. The risk map to be designed by adding these indicators will support more effective decisions. Objective: The research aims to propose a clustering scheme to design a risk map of cities for Turkey. Methodology: The unsupervised clustering algorithm suggested dividing the cities of Turkey into clusters, considering health, socio-economic, environmental indicators, and the spread pattern of COVID-19. Results: We found that cities are clustered into five groups while megacity Istanbul alone formed a cluster, three of Turkey's largest cities formed another cluster. Other clusters consist of 19, 26, and 32 cities, respectively. The most important determinants which have predictive power are identified. Conclusion: The suggested clustering method can be a decision support system for policymakers to determine the differences and similarities of cities in quarantine decisions and normalization phases for the following periods of the pandemic. Originality: To the best of our knowledge, this study differs from previous studies because countries were grouped in previous studies by only considering the confirmed cases. In this study, cities were clustered in terms of the health, socio-economic, and environmental indicators to make decisions locally. Limitations: The distribution of confirmed cases by age could be added, especially to make decisions about education, but this data is not officially announced.
AtıfWoS1OpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ1Enhancing Burnability Characteristics of Low-Temperature Burnt-Cement Clinker by Recycling Phosphogypsum Wastes
Aksan, U.; Köseoglu, K.; Gökçe, H. S.
In the present study, the effect of phosphogypsum, a byproduct from the phosphoric acid production industry, on the clinkerization process was researched in order to improve the burnability of clinkers at lower burning temperatures. Raw meal samples containing phosphogypsum at 0%, 1%, 3%, and 5% by weight were burned at 1,350 degrees C, 1,400 degrees C, 1,450 degrees C, and 1,500 degrees C. The introduction of phosphogypsum reduced the presence of unbounded (free) CaO relatively up to 43%. Thus, the mineralization effect of phosphogypsum promotes lower burning temperatures. The free CaO content of the 5% phosphogypsum containing clinker decreased to 0.94% at 1,400 degrees C after 120 min of burning time. The free CaO content was found to be almost identical (0.75%) to that of industrial clinker burned in a rotary kiln at 1,500 degrees C. Due to the low free CaO content (<1%) and the burnability index (73), the recycling of phosphogypsum wastes was found to be suitable for the production of eco-efficient clinkers. The reduced energy consumption and energy-related CO2 emissions in such modified clinkers can contribute to the economic and ecological goals of the cement industry. (C) 2021 American Society of Civil Engineers.
AtıfWoS2OpenAlex3İncele - Derleme MakaleAçık Erişim2021Scopus SJRQ1Alkali-activated and geopolymer materials developed using innovative manufacturing techniques: A critical review
Gökçe, H.S.; Tuyan, M.; Nehdi, M.L.
The manufacturing of geopolymers and alkali-activated materials for precast and cast in-situ construction applications could be achieved using suitable production techniques, such as one-part production, pre-setting pressure and hot pressing, two-stage concreting, and 3-dimensional printing. Adequate selection and tailoring of the manufacturing methodology are imperative for overcoming characteristic application problems of these materials and achieving eco-efficiency and superior engineering properties. With distinctive benefits including rapid solidification, lower cost, saving natural resources, less energy consumption, and reduced carbon footprint, alkali-activated and geopolymer composites have emerged as a strong contender for replacing conventional concrete in diverse construction applications. Critical analysis of the literature on innovative production methods indicates that the one-part production technique is promising for the eliminating design complexity of these mixtures. The pre-setting pressure and hot pressing applications would allow the achievement of superior physical and mechanical characteristics in a short period of time, especially for the precast industry. The workability and setting problems of alkali-activated materials could be overcome using the two-stage concreting methodology. To be used in 3D printing of alkali-activated and geopolymer materials, remarkable development is required in terms of rheological aspects. Accordingly, this paper surveys pertinent and recent literature and critically reviews the state-of-the-art of alternative production techniques of alkali-activated and geopolymeric materials, along with its use in recent applications, identifies pertinent knowledge gaps, and defines future research directions.
AtıfScopus155WoS137OpenAlex167İncele
