Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Book Part Citation - Scopus: 5Turmeric Starch: Structure, Functionality, and Applications(Elsevier, 2023) Rasmi, Y.; Demir, Mustafa Muammer; Kırboğa, K.K.; Tekin, B.; Demir, M.For many years, starch has been a subject of never-ending study. It is a relatively affordable substance widely used in food and non-food applications. Fresh rhizomes of Curcuma longa L. and Curcuma caesia extract turmeric starch (Zingiberaceae). Turmeric starch is a common food ingredient used in the thickening of soups and making syrups and other sugars. It is easily modified and finds many uses in industries such as adhesives, paper products, anti-sticking agents, and textile manufacturing. Morphological characteristics such as the shape and size of starch granules vary significantly, and further studies are expected for Turmeric starch, with promising results and increasing the usefulness of starches in industries. This book chapter outlines recent developments in understanding starch isolation, chemical composition, morphology, pasting, rheological and thermal characteristics, and various applications of turmeric starch. Potential applications of oat starches are also reviewed. © 2024 Elsevier Inc. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 5Experimental Modeling of Antimony Sulfides-Rich Geothermal Deposits and Their Solubility in the Presence of Polymeric Antiscalants(Elsevier, 2022) Karaburun, Emre; Sözen, Yiğit; Çiftçi, Celal; Şahin, Hasan; Baba, Alper; Akbey, Ümit; Yeşilnacar, Mehmet İrfan; Erdim, Eray; Regenspurg, Simona; Demir, Mustafa MuammerAntimony (Sb)-rich geothermal deposits have been observed in many geothermal power plants worldwide. They occur as red-colored, sulfidic precipitates disturbing energy-harvesting by clogging the geothermal installations. In order to prevent the formation of this scale, information on its physicochemical features is needed. For this purpose, Sb-rich sulfide-based deposits were synthesized at controlled conditions in a pressurized glass reactor at geothermal conditions (135 °C and 3.5 bar). Various polymeric antiscalants with different functional groups, such as acrylic acid, sulphonic acid, and phosphonic acid groups were tested for their effect on Sb sulfide solubility. An additional computational study was performed to determine the binding energy of Sb and S atoms to these groups. The results suggest that sulfonic acid groups are the most affective. Therefore, it was concluded that these macromolecule containing sulfonic acid groups and poly (vinyl sulfonic acid) derivatives could potentially act as antiscalants for the formation of antimony sulfide.Article Citation - WoS: 10Citation - Scopus: 10Hydrogeology and Hydrogeochemistry of the Geothermal Systems and Its Direct Use Application: Balçova-Narlıdere Geothermal System, İzmir, Turkey(Elsevier, 2022) Baba, Alper; Sözbilir, Hasan; Sayık, Tolga; Arslan, Sinan; Uzelli, Taygun; Tonkul, Serhat; Demir, Mustafa MuammerThe Balçova-Narlıdere geothermal system, located in western Turkey, is an extensional domain type geothermal play. Geological, hydrogeological, and geothermal studies have been done in the Balçova-Narlıdere geothermal field since 1960. As a result of these studies, production and research wells were drilled in the area by both the public and private sectors. Of the 37 wells drilled in the Balçova-Narlıdere geothermal field, 26 were drilled by İzmir Geothermal Energy Company Inc. (16 productions, 4 re-injection, 4 gradientst, 2 unused) and 11 by the İzmir Governorship Investment Monitoring and Coordination Department and companies in the private sectors. There are two reservoirs, one shallow and one deep, in the geothermal field. Well depths are less than 200 m in the shallow reservoir. The deep production wells have depths ranging from 400 to 1,100 m and reservoir temperatures reaching 140 °C. The electrical conductivity (EC) values in the shallow production wells range from 1,200 to 1,500 µS/cm. EC values in the deep production wells vary from 1,871 to 2,025 µS/cm, and all geothermal fluids in the field are mineral-rich waters. In the İzmir geothermal district heating system, the newest technologies are used, and operational costs are very low. İzmir Geothermal Energy Company Inc. has been operating since 1996 and has reached 38,460 residences. The current capacity of the system is approximately 160 MWt. Cooling systems continue to spread in Turkey, focusing on electric air conditioning systems and geothermal heating systems, but both economic and applicability problems have slowed the expansion of cooling systems. However, İzmir Geothermal Energy Company Inc. began operating its first geothermal cooling application in Balçova in 2018, cooling 1,900 m2 of the indoor area by lithium bromide absorption and 90/85 °C geothermal temperature regime by supplying 6/9 °C clean cold water to the coolers in the buildings. These results show that the extensional domain type geothermal system in the Balçova-Narlıdere region is suitable for both heating and cooling applicationsArticle Citation - WoS: 3Citation - Scopus: 6Hybrid Photonic-Plasmonic Mode-Coupling Induced Enhancement of the Spontaneous Emission Rate of Cds/Cdse Quantum Emitters(Elsevier, 2022) Gökbulut, Belkıs; İnanç, Arda; Topçu, Gökhan; Özçelik, Serdar; Demir, Mustafa Muammern this paper, a hybrid photonic-plasmonic resonator, which comprises an electrospun polymer fiber with a micrometer diameter and a core/shell nanostructure with a gold nanoparticle core, is constructed to investigate the dynamics of the coupled spontaneous emission of CdS/CdSe quantum dots (QDs). The gold nanoparticle core; covered with a silica shell, anchored with individual CdS/CdSe QDs, is placed inside a hollow cylindrical nanocavity formed on the surface of the microfiber to enable integration of the optical mode with the plasmonic effect, which is induced by the localized surface plasmons of the metal nanoparticle being present in the vicinity of the dipoles. The spontaneous emission rate of the QDs, coupled into the hybrid photonic-plasmonic mode, is measured to enhance by a factor of 23 via a time-resolved experimental technique. This result suggests that the regeneration of the optical mode-field inside the photonic-plasmonic resonator through the interaction of the dipoles with the localized surface plasmons of a metal nanoparticle strongly enhances the density of the electromagnetic states of the quantum emitters to facilitate an enhanced spontaneous emission within the host medium of the proposed polymer based-photonic structure.Article Citation - WoS: 9Citation - Scopus: 7Understanding the Impact of Sri2 Additive on the Properties of Sn-Based Halide Perovskites(Elsevier, 2022) Yüce, Hürriyet; Perini, Carlo A. R.; Hidalgo, Juanita; Castro-Mendez, Andres-Felipe; Evans, Caria; Demir, Mustafa MuammerOrganic-inorganic halide perovskites have been identified as favorable candidates for the next generation of photovoltaics. Adding alkali metal halides to perovskite films has been shown to be a viable option to improve the perovskite film quality and to modulate their fundamental properties. In this work, we perform optical and electron-beam based characterizations of mixed Sn/Pb based perovskite films to investigate the effect of the addition of the alkaline metal halide SrI2. By analyzing structural (X-ray diffraction), morphological (Scanning Electron Microscopy), optical (photoluminescence), and chemical properties (X-ray photoelectron spectroscopy), we show a complex interplay of effects upon addition of Sr2+ into the perovskite solution. Low concentrations of Sr2+ increases lattice strain, which hints at incorporation of the additive into the perovskite lattice and improves the film optoelectronic properties. As the additive concentration increases beyond 0.5 mol %, microstrain decreases. At concentrations >0.5 mol %, Sr2+ induces significant reduction of the average domain size, which impacts both structural and optical properties of the perovskite film.Article Citation - WoS: 3Citation - Scopus: 5Plasmon-Induced Spectral Tunability of Perovskite Nanowires(Elsevier, 2021) Gökbulut, Belkıs; Topçu, Gökhan; Demir, Mustafa Muammer; İnci, Mehmet NaciIn this paper, plasmon-assisted spectral tunability in random media, composed of Perovskite (CsPbBr3) nanowires surrounded by Au nanoparticle clusters in polystyrene matrix, is achieved. The interaction between the surface plasmons and the quantum sources is observed to generate photoluminescence from the higher excited state energy levels of the excited semiconductor nanowires, which results in a blueshifted fluorescence emission of 50 nm. The localized surface plasmon properties are also determined to be tuned by plasmonic pumping of the quantum sources at different resonant frequencies. Thus, the first observation of the tunable blueshifted fluorescence emission of the semiconductor nanocrystals surrounded by plasmonic nanoparticle aggregates is achieved. The dramatic changes in the spectral profiles of the fluorescent nanowires are attributed to be due to the fast dynamics surface enhanced fluorescence mechanism.Article Citation - WoS: 14Citation - Scopus: 16Bodipy-Based Organic Color Conversion Layers for Wleds(Elsevier, 2020) Yüce, Hürriyet; Güner, Tuğrul; Dartar, Suay; Kaya, Beraat Umur; Emrullahoğlu, Mustafa; Demir, Mustafa MuammerThe usage of organic dyes in phosphor conversion layer of WLED is an attractive approach since they have high molar extinction coefficient and photostability. Various types of organic pigments have been employed for this purpose such as BODIPY, perylene diimide, Rhodamine B, pyrene, Nile red, etc. Among those, BODIPY-based organic dyes appear to be promising candidate for white light generation. In this work, for the first time, red and green emitting BODIPY-based organic molecules have been used as colour conversion layer. These molecules were associated with PMMA in DMF solution and the resulting solution was subjected to electrospinning. Colorful electrospun mats were embedded into PDMS matrix and their free-standing PDMS composite films were used as color conversion layers over blue LED to produce white light such that CRI of 95 and CCT of 4200 K was achieved. These values show that BODIPY-based organic molecules containing fiber composites are promising candidates to be used as color conversion layers for white light applications.Article Citation - WoS: 50Citation - Scopus: 58Chemically Modified Optical Fibers in Advanced Technology: an Overview(Elsevier, 2019) Shukla, S. K.; Kushwaha, Chandra Shekhar; Güner, Tuğrul; Demir, Mustafa MuammerIn recent years, chemically modified optical fibers have widely used for development of several advanced chemical and biosensors, biomedical technology and environmental monitoring. The chemically modified optical fiber bears several valuable properties like energy loss, catalytic behaviour, refractive index, and mechanical strength to advance the optical fiber technology. In this article, we reviewed the chemically-modified optical fiber and their applications in different optical fiber-based technologies. The basics of optical fiber and their modification are discussed along with the adopted methodologies. The advancements in different optical fiber based technologies viz sensing, imaging, tomography, magnetic resonance imaging, photodynamic therapy, optogenics, surgery and environmental monitoring are discussed in the light of the contribution of chemically modified optical fibers. In conclusion, success and challenges for the use of chemically modified-optical fiber are presented on the basis of existing literature.Article Citation - WoS: 25Citation - Scopus: 28Colorimetric and Plasmonic Pressure Sensors Based on Polyacrylamide/Au Nanoparticles(Elsevier, 2019) Topçu, Gökhan; Güner, Tuğrul; İnci, Ezgi; Demir, Mustafa MuammerColorimetric stimuli-responsive nanomaterials have emerged as an eminent tool for sensor applications. Among this class of sensing elements, gold nanoparticle-based (Au NP) nanostructures are promising materials due to their plasmonic features. In this study, free-standing flexible polymeric films having intense optical response upon application of mechanical pressure were fabricated based on polyacrylamide (PAAm) and Au NPs. Pressure may cause plasmonic shift most probably due to the disassembly of the clusters from blue to reddish individual particles depending on the extent of pressure. Temperature, time, and extent of pressure were examined in terms of spectral change of Au particles. The sensor films depict working range up to 160 MPa, which shows minor change at elevated temperatures probably due to the stress induced crystallization of PAAm. For practical applications, a simple red-green-blue (RGB) space-based algorithm was presented for smartphone-assisted detection of applied pressure. Moreover, the PAAm/Au composite structure shows self-healing without any additive under ambient conditions even after divided into pieces. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Triboluminescent Composite Microspheres Consisting of Alginate and Eud(4)tea Crystals(Elsevier, 2018) İncel, Anıl; Demir, Mustafa MuammerAlginate is utilized to obtain luminescent composite microspheres containing europium tetrakis (dibenzoylmethide) triethylammonium (EuD4TEA) triboluminescent (TL) crystals. Na alginate is initially treated with Ca(II) and then Eu (III) so that physically-crosslinked alginate microspheres were obtained. EuD4TEA crystals are precipitated in situ on the surface of the spheres upon treatment with dibenzoylmethane (DBM) and triethylamine (TEA). The EuD4TEA/alginate composite spheres are swollen in aqueous system, the diameter of the microspheres increases from 180 up to 405 pm in 48 h. TL intensity of the spheres swollen in 1 h decreases 4 folds compared to dry spheres; however, it systematically increases as the swelling time is extended step-wise to 48 h. Swelling may develop structural homogenity in the microsphere that supresses the optical scattering and may lead to better transmittance of the TL signal. (C) 2017 Elsevier B.V. All rights reserved.