Izmir Institute of Technology

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AAS, XRPD, SEM/EDS, and FTIR studies of the effect of calcite and magnesite on the uptake of Pb2+ and Zn2+ ions by natural kaolinite and clinoptilolite
(Izmir Institute of Technology, 2005) Zünbül, Banu; Shahwan, Talal
In this study, the effect of magnesite and calcite on the uptake of lead and zinc ions by mixtures of these carbonates with kaolinite and clinoptilolite was investigated at various loadings and mixture compositions. The concentration of both ions in the liquid phase was in measured using AAS, while XRPD, SEM/EDS, and FTIR techniques were used in characterizing the solid samples. Thestudy included the determination of kinetics and sorption isotherms of lead and zinc on pure kaolinite and clinoptilolite. Moreover, the sorption behavior of lead and zincat different concentrations and pH conditions was investigated on mixtures of calcite and magnesite with kaolinite and clinoptilolite at carbonate mass percentage compositions of 5, 10, 25, 60 in addition to pure calcite and magnesite. The morphologies of theformed precipitates, the plausible structural change in the lattice of calcite, magnesite, kaolinite, and clinoptilolite originating from sorption of lead and zinc ions was examined. According to obtained results, the sorption affinity of kaolinite and clinoptilolite towards lead is larger than their affinity towards zinc. Within the operating experimental conditions, the sorption capacity increased with increasing the amountsof calcite, and magnesite. The overall order of retention of lead and zinc was observed as magnesite . calcite> clinoptilolite> kaolinite under neutral and alkaline pH conditions and high loadings. When the initialconcentration of zinc and lead ions is raised to saturation conditions, rapid overgrowth of cerussite and hydrozincite was observed. Increasing the initial pH to 10,0 causedenhancement in the dissolution of calcite and magnesite, leading to the enhancingthe precipitation of hydrozincite, and an increased formation of hydrocerussite instead ofcerussite. The uptake of Zn2+ and Pb2+ions by calcite and magnesite have lead to modifying the geometry of the carbonate groups, the thing reflected as variation in their vibrational bands.
Abelian-Non Abellian mixing and cosmic inflation in Born-Infeld type gravity
(Izmir Institute of Technology, 2013) Altaş, Aslı; Demir, Durmuş Ali
General Relativity (GR), which forms the basic framework for understanding cosmological and astrophysical phenomena, is based solely on general covariance. Therefore, the theory admits extensions regarding various phenomena related to inflation, massive gravity, dark energy etc. In this thesis work we study Born-Infeld type extensions of the GR. There are mainly two parts in the thesis: The extension based on Ricci tensor (already known in literature) and a novel extension based on Riemann tensor. We call them respectively Born-Infeld-Einstein (BIE) and Born-Infeld-Riemann (BIR) extensions. The BIR formalism is being proposed and studied in this thesis work. In a comparative fashion, we study these two extensions for determining their implications for 1. Mixing between Abelian and Non-Abelian gauge fields, and 2. Inflationary phase of cosmic evolution. As we prove explicitly, the two approaches yield distinct predictions for these phenomena. We emphasize that a slow-roll inflationary dynamics is naturally realized in BIR. The mixing between Abelian and Non-Abelian sectors enables cosmic photon production in inflationary phase.
Activated signaling pathways and apoptotic mechanisms in resveratrol applied chronic myeloid leukemia cells and the involvement of ceramide metabolizing genes on these mechanisms
(Izmir Institute of Technology, 2010) Kartal Yandım, Melis; Baran, Yusuf
Resveratrol, an important phytoalexin in many plants, has cytotoxic effects on several cancer cells. Ceramide is a significant sphingolipid which affects many signaling pathways regulating cell senescence, migration, and cell cycle arrest. Intracellular ceramide level is balanced by glucosylceramide synthase (GCS), the converter of ceramide to glucosylceramide, and sphingosine kinase-1 (SK-1) that convert ceramide to sphingosine 1-phosphate (S1P). Ceramide functions as an apoptotic molecule whereas glucosylceramide S1P function as anti-apoptotic. An important cell-permeable analogue of natural ceramides, C8:ceramide, increases intracellular ceramide levels significantly, while 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and SK-1 inhibitor increase accumulation of ceramides by inhibiting GCS and SK-1, respectively. Chronic myelogenous leukemia (CML), a hematological disorder, results from the generation of BCR/ABL oncogene. In this study, we examined the roles of ceramide metabolizing genes in resveratrol-induced apoptosis, and the expression profiles of 84 genes underlying apoptosis, cell cycle control, DNA damage repair, and invasion and metastasis in human K562 CML cells treated with resveratrol. There were synergistic cytotoxic and apoptotic effects of resveratrol with coadministration of C8:ceramide, PDMP and SK-1 inhibitor. We observed significant increases in expression levels of LASS genes, and decreases in expression levels of GCS and SK-1 in K562 cells in response to increasing concentrations of resveratrol. There were also significant increases in the expression levels of SERPINB5, FAS, TNFRSF, MTSS that are related with tumor suppression, and decreases in Myc expression. Our data, in total, showed for the first time that resveratrol might kill CML cells through increasing intracellular generation and accumulation of apoptotic ceramides.
Acylation of 2-methoxynaphthalene over Ion-exchanged beta zeolite
(Izmir Institute of Technology, 2002) Kantarlı, İsmail Cem; Artok, Levent
Friedel Crafts acylation of 2-Methoxynaphthalene was carried out over various ion-exchanged . zeolites (Mn+., where Mn+: In3+, Zn2+, Al3+, Fe3+, La3+) with various anhydride (acetic, propionic and benzoic anhydrides), or acyl chloride (acetyl, propionyl and benzoyl chlorides) acylating reagents. The results suggested that selectivity towards the 6-substituted products was higher with the larger size anhydrides, propionic and benzoic anhydrides. The metal cation type within the zeolite significantly influenced the extent of conversion and product distribution. That La3+ exchanged zeolite displayed higher selectivity for the 6-position acylated product with anhydrides ascribed mainly to narrowing of channels by the presence of La(OH)2+ ions that leave no room for the formation of more bulky isomeric forms and to enhanced Bronsted acidity of the zeolite. With acyl chlorides, the recovery of ketone products was found to be remarkably low. 1-Acyl-2-methoxynaphthalenes actively underwent deacylation when acyl chlorides were used as the acylation reagent.
AEG and Peter Behrens: Symbolism in the first corporate identity design
(Izmir Institute of Technology, 2012) Boztepe, Uygar; Yücel, Şebnem
Some historians called Peter Behrens' designs for AEG as first corporate identity design without a detailed analysis. Another group of the historians claimed that his works for AEG were shaped by only function or machine-aesthetic. Even some of these historians saw Behrens' works as inceptors of functionalism or rationalism in modern architecture. This thesis attempts to fill the gap in literature by analyzing Behrens' works for AEG in order to understand whether his designs formed a corporate identity or not. In order to show the shortcomings of such readings, the thesis explores the symbols that were used in the designs of Behrens, even in his most-functionalist design-works. The discussion was carried out through analysis of Behrensâ€™ and his contemporariesâ€™ written and design works, with materials available in Klingspor, Mathildenhöhe and TechnikMuseum Berlin Archives. This analysis is done through a review of scientific management techniques and their reflections in architectural culture and by parallel readings of literature and architecture in Germany at the turn of the century. As the discussion of the thesis pointed out, Peter Behrens' designs for AEG can be called as first corporate identity design since they have a consistent design vocabulary. While designing for AEG Behrens used scientific management and mass-production techniques in his designs. However these were not the only forces that shaped his design-work. One can see the vestiges of the symbols in his works that are coming from literature and antiquity. The thesis argues that it is not possible to fully understand the architecture of Behrens without understanding symbols. The thesis hopes to make a new reading of modern architecture from a different point of view, which includes a discussion on symbolism in modern architecture, avoiding oversimplification and reductionism present in readings with functionalist focus.
Antimicrobial and antioxidant activities of Turkish extra virgin olive oil from different varieties
(Izmir Institute of Technology, 2009) Karaosmanoğlu, Hande; Soyer Dönmez, Ferda
Olive oil is the main source of fat in Mediterranean diet. The major active components of olive oil include oleic acid, phenolic compounds and squalene which have different benefits such as cancer prevention, antimicrobial and antioxidant activities, and lowering the incidence of skin cancer, respectively. In recent years, the number of studies about the biochemical properties of different varieties of olive oils and their phenolic contents has dramatically increased.In this study, Turkish EVOO from different varieties and their phenolic compounds were investigated in terms of their antimicrobial and antioxidant properties as well as refined olive, hazelnut and canola oils. Antimicrobial activities of EVOOs and ten phenolic compounds were tested against three foodborne pathogenic bacteria, Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Enteritidis which are the foremost bacterial cause of the largest number of outbreaks, cases and deaths in the world. While all EVOOs showed bactericidal effect the phenolics demonstrated slight antimicrobial activity with percent inhibition between 0-25 of growth rate of bacteria. Moreover, refined olive, hazelnut and canola oils did not show any antimicrobial activity.Finally, antioxidant activities of EVOOs, refined olive, hazelnut and canola oils were determined by B-carotene-linoleic acid model system and ABTS radical scavenging method. According to B-carotene-linoleic acid method, it was observed that antioxidant activities of oil samples varied between 21.19% and 64.54%. On the other hand, it was found that free radical scavenging activities varied between 1.21% and 21.97% as a result of ABTS method. These results were correlated with TPC values of oils.
Antimicrobial properties of silk fibroin-carrageenan films incorporating grape seed extract
(Izmir Institute of Technology, 2009) Arserim Uçar, Dilhun Keriman; Korel, Figen
In this study antimicrobial edible films were developed by incorporation of grape seed extract into silk fibroin-carrageenan films. Developed films were subjected to instrumental analysis such as scanning electron microscopy, atomic force microscopy, X-ray diffractometer, and Fourier transform infrared spectrometer for the characterization of the film. The antimicrobial activity of silk fibroin-carrageenan films on different bacteria including Listeria innocua, Staphylococcus aureus, Staphylococcus carnasus, Bacillus amyloliquefaciens, Escherichia coli, Pseudomonas fluorescens, Escherichia coli O157:H7, and Salmonella Typhimurium, on raw chicken breast meat and beef sausages were tested. Application of silk fibroin-carrageenan films incorporating grape seed extract and/or Na2EDTA on chicken breast meat and beef sausages demonstrated the efficacy of these films to enhance the microbial quality of the products. Increasing the concentration of grape seed extract in the films increased the antimicrobial activity of the films in food applications. It is found that silk fibroin-carrageenan films incorporating grape seed extract could be used to control the growth of S. aureus on beef sausages during 28 days of storage at 4 C. The use of these films on beef sausages had significant effect on moisture content of the sausages as well as the textural properties of the sausages. This study indicated the potential of using silk fibroin-carrageenan films incorporating grape seed extract to be used as an antimicrobial edible food packaging.
Apollonius representation and complex geometry of entangled qubit states
(Izmir Institute of Technology, 2018-07) Parlakgörür, Tuğçe; Pashaev, Oktay
In present thesis, a representation of one qubit state by points in complex plane is proposed, such that the computational basis corresponds to two fixed points at a finite distance in the plane. These points represent common symmetric states for the set of quantum states on Apollonius circles. It is shown that, the Shannon entropy of one qubit state depends on ratio of probabilities and is a constant along Apollonius circles. For two qubit state and for three qubit state in Apollonius representation, the concurrence for entanglement and the Cayley hyperdeterminant for tritanglement correspondingly, are constant along Apollonius circles. Similar results are obtained also for n- tangle hyperdeterminant with even number of qubit states. It turns out that, for arbitrary multiple qubit state in Apollonius representation, fidelity between symmetric qubit states is also constant along Apollonius circles. According to these, the Apollonius circles are interpreted as integral curves for entanglement characteristics. For generic two qubit state in Apollonius representation, we formulated the reflection principle relating concurrence of the state, with fidelity between symmetric states. The Möbius transformations, corresponding to universal quantum gates are derived and Apollonius representation for multi-qubit states is generated by circuits of quantum gates. The bipolar and the Cassini representations for qubit states are introduced, and their relations with qubit coherent states are established. We proposed the differential geometry for qubit states in Apollonius representation, defined by the metric on a surface in conformal coordinates, as square of the concurrence. The surfaces of the concurrence, as surfaces of revolution in Euclidean and Minkowski (Pseudo-Euclidean) spaces are constructed. It is shown that, curves on these surfaces with constant Gaussian curvature becomes Cassini curves. The hydrodynamic interpretation of integral curves for concurrence as a flow in the plane is given and the spin operators in multiqubit |PP...P states are discussed.
Applications of electrospun nanofibers in filtration processe
(Izmir Institute of Technology, 2013) Horzum Polat, Nesrin; Elçi, Latif
Electrospinning is a simple and versatile method to fabricate ultrathin fibrous mats from a wide variety of organic and/or inorganic materials. Since it allows fabricating fiber diameter and surface/internal structures by solution and instrumental parameters, electrospun fibers provide much enhanced functionalities, which can not be obtained by bulk materials. This thesis examines the filtration, sensing and catalytical applications associated with the remarkable features of electrospun nanofibers. The systems studied are reported herein; (i) The first part of this dissertation deals with the filtration applications of electrospun nanofibrous membranes.  Nano-sized chitosan fibers were utilized for sorption of Fe(III), Cu(II), Ag(I), and Cd(II) ions from aqueous solutions.  The surface of chitosan fibers were further functionalized by monodisperse nano zero-valent iron (nZVI) particles for the removal of inorganic arsenic species.  Sorption of radioactive U(VI) ions from aqueous systems via column sorption under continuous flow was performed using amidoximated polyacrylonitrile fibers. (ii) The second part of this dissertation presents sensing applications of ceramic fibers.  Humidity sensing properties of electrospun ZnO fiber mats were investigated by quartz crystal microbalance (QCM) method and electrical measurements.  Electrospinning technique was used as coating process for deposition of CeO2/ZnO and ZnO based nanofibers on the electrode of QCM. The fiber-coated QCM sensors were used for the detection of volatile organic compounds (VOCs). (iii) The last part of this dissertation describes an approach to fabricate hierarchically structured composite nanofibers. The nanostructured materials prepared by the simultaneous electrospinning of CeO2 and LiCoO2 precursors and SiO2 nanoparticles were used for the photocatalytic degradation of Rhodamine B.
Architecture of societies in multicultural region: The case of vernacular architecture at Datça Peninsula
(İzmir Institute of Technology, 2005) Kaya, Can; Ergül, M. Emre
Mediterranean Basin is one of the oldest settlement areas in the world with its 9000 years of history. The interaction between societies, which got even stronger with the organized trade routes in the area, is the most characteristic property of the Mediterranean Basin. The Aegean and Mediterranean shores of Anatolia witnessed the shared lives of Turkish-Muslims, Greek-Orthodox, and even the Italians for more than 500 years. That's why it is possible to call this area, as "interference zone" or "transition region".One of the areas that is located on Anatolia's interference zone is Datça Peninsula. This thesis is conducted over the vernacular building stock that was built in the peninsula from the 19th century to mid 20th century. The settlements of ÇesÌ§me District and Yaka Village, are comprehended in this thesis. One roomed living units are named as main units. Main units and its fireplaces were examined. The tables, that show the size and location of the fireplace, were constituted. Analysises were done over these tables. The aim is to document the building stock in this area and to analyse on the fireplace. Consequently, it was discovered that the main units have clues belonging to Turkish Room, such as seki üstü / seki altı. It was also understood that the fireplace is the pre-condition of identifying the unit as living space.
Artificial neural networks and fuzzy logic applications in modeling the compressive strength of portland cement
(Izmir Institute of Technology, 2004) Can, Sever; Akkurt, Sedat
Portland cement production is a complex process that involves the effect of several processing parameters on the quality control of 28-day cement compressive strength (CCS). There are some chemical parameters like the C3S, C2S, C3A, C4AF, and SO3 contents in addition to the physical parameters like Blaine (surface area) and particle size distribution. These factors are all effective in producing a single quantity of 28-day CCS. The long duration of 28 day CCS test provided the motivation for research on predictive models. The purpose for these studies was to be able to predict the strength instead of waiting for 28 days for the test to be complete. In this thesis, artificial intelligence (AI) methods like artificial neural networks (ANNs) and fuzzy logic were used in the modeling of the 28-day CCS. The two models were compared for their quality of fit and for the ease of application.Quality control data from a local cement plant were used in the modeling studies. The data were separated randomly into two parts: the first one contained 100 data points to be used in training and the second part had 50 data points to be used in testing stages of the models. In this study, four different AI models were created and tested (3 ANN, 1 fuzzy logic). One of the ANN models (Model A) had 20 input parameters in 20x20x1 architecture with testing average absolute percentage error (AAPE) of 2.24%. The other ANN model (Model B) had four input parameters (SO3, C3S, Blaine and total alkali amount) in 4x4x1 architecture with AAPE of 2.41%. Both of the Model A and the Model B were created in the MatLAB® environment by writinga custom computer code. The last ANN model (Model C) actually refers to 72 differentANN models created in the MatLAB® neural networks toolbox. In order to obtain a model with the lowest error, different learning algorithms, training functions and architectures in combinations were tested. The lowest AAPE among these models appeared to be 2.31%. The fuzzy logic model (Model D) which had four input parameters (SO3, C3S, Blaine and total alkali amount) was created in the MatLAB fuzzy logic toolbox. In order to write the fuzzy rules, the sensitivity analysis of the Model B was utilized. The AAPE of the Model D was 2.69%. The model was compared with the ANN models for its error levels and ease of application. The results indicated that through the application of fuzzy logic algorithm, a more user friendly andmore explicit model than the ANNs could be produced within successfully low error margins.
Assessment of land use change impacts on hydrological parameters in Porsuk River Basin - Turkey
(01. Izmir Institute of Technology, 2023-07) Zulal, Khalilullah; Gündüz, Orhan; Alp, Emre
Land Use Land Cover (LULC) change is considered to play an essential role in river basin hydrology. Climate change, and increase in urbanization have disrupted the hydrological parameters pattern in Porsuk River Basin (PRB). The current study is aimed to investigate the LULC change impacts on surface runoff, groundwater, evapotranspiration, and lateral flow parameters in the five sub-basins of the PRB under different LULC development scenarios (1990 & 2006) and one climate period (1989- 2010) through hydrological modeling. In this study, the Soil and Water Assessment Tool (SWAT) model was utilized to analyze the hydrology of the river basin at watershed scale. The hydrological pattern characterization is based on five discharge gauges monitored by State Hydraulic Works (DSI) in the basin. The Kiranharmani, Parsibey, and Porsuk Ciftligi subbasins, the yearly increase in surface runoff reached 25%, 18%, and 12.91%, respectively, are more affected by landuse changes. The Scenario 2, contrary to Scenario 1, showed a noticeable reduction of groundwater infiltration in all subbasins with exception of Parsibey, due to rapid increased area of residential regions. In comparison to the 1990 LULC, changes in the 2006 LULC have a greater overall impact on hydrological processes in all sub-basins of the PRB. Therefore, it is believed that changes in specific LULC classifications can be linked to the reaction to changes in hydrological processes in a subbasin. Overall, this research is believed to be among the first to be done in the PRB, and the findings are thought to be helpful for water management.
Asymmetric synthesis and anti-tumor properties of conformationally constrained analogues of (S)-and (R)-goniothalamin
(Izmir Institute of Technology, 2008) Kasaplar, Pınar; Çağır, Ali
Naturally isolated 5-substituted-a,B-unsaturated-.-lactones gained great attention of researchers due to their cytotoxic and anti-tumor properties. Styryl lactones are the most interesting members of this group of naturally available compounds. One of the well-known and important example for styryl lactone is goniothalamin, which shows cytotoxicity against variety of cancer cell lines. This cytotoxic property was shown to be selective for cancer cell lines with no significant cytotoxicity toward non-malignant cells. Recent structure activity relationship (SAR) studies on goniothalamin shows that R configuration on its stereogenic center, trans double bonded linker and Michael acceptor parts of the molecules are essential for its cytotoxic activity. In this study conformationally constrained analogues of (S)- and (R)-goniothalamin were synthesized. Syntheses were started with the catalytic asymmetric allylation of benzaldehyde, naphthaldehyde and quinaldehyde derivatives in the first step, then formed alcohols were acrylated with acryloyl chloride to yield the corresponding esters, in the last step, ring closing metathesis with Grubbs. catalyst yielded the target molecules. Meanwhile, in this study the synthesized 5-aryl-substituted-a,B-unsaturated-S-lactones were tested to determine their cytotoxicity against MCF-7, PC-3, DU-145 and LNCAP cancer cell lines.
Asymmetric synthesis of 5,6-dihydro-2H-pyran-2-one derivatives
(Izmir Institute of Technology, 2014-09) Akçok, İsmail; Çağır, Ali
α,β-unsaturated lactone derivatives are very important structural core which are isolated from nature and shown as source for several biological activities. Biologically active styryl δ-lactones are well known α,β-unsaturated-δ-lactones. Up to date, many α,β- unsaturated-δ-lactones and their analogues have been isolated and synthesized, exhibiting promising anti-proliferative properties against different cancer cell lines. In this thesis, large scale asymmetric syntheses of (R)-4’-methylklavuzon and (R)- 2’-methylklavuzon were completed successfully. Also, syntheses of heteroatom functionalized naphthyl substituted novel α,β-unsaturated-δ-lactone (5,6-dihydro-2Hpyran- 2-one) derivatives, α,β-unsaturated-γ-lactone (furan-2(5H)-one) derivatives and 7- membered α,β-unsaturated lactone (6,7-dihydro-5H-oxepin-2-one) derivatives were accomplished. Development of a method for one-pot synthesis of 6-membered α,β-unsaturated- δ-lactone was also studied, and a new vinylogous aldol addition method was developed. By this method, new α,β-unsaturated methyl esters were prepared via dienolate formation starting with methyl buten-3-oate.
Born-Infeld-Riemann gravity
(Izmir Institute of Technology, 2012) Soysal, Selin; Demir, Durmuş Ali
The Universe we live in has started with a bang, a very big bang. Its evolution and global structure are controlled by gravitation and its matter and radiation content. Gravitation, curving of spacetime, formulated in minimal or extended versions, provides different layers of understanding about the Universe. Einstein's General Relativity (GR) gives a description of gravity, and there are various reasons for extending it. One such extension refers to unifying the other forces in Nature with gravity in the framework of GR. The very first approach in this direction was due to Born and Infeld who have tried to unify electromagnetism with gravity. It is a generalization of metric tensor to have both symmetric and antisymmetric parts gives rise to a merging of Maxwell's theory with Einstein's theory. In later decades, attempts have been made to unify the other forces as well. In this thesis study, we extend Born-Infeld gravity to unify gravity with non- Abelian forces in a natural way. This, which we call Born-Infeld-Riemann gravity, is accomplished by devising a gravity theory based on Riemann tensor itself and subsequently generalizing this tensor to naturally involve gauge degrees of freedom. With this method, preserving the successes of Born-Infeld gravity, we are able to combine Yang- Mills fields (W, Z bosons as well as gluons) with gravity. We perform a phenomenological test of our approach by analyzing cosmic inflation generated by non-Abelian gauge fields.
Borylation of petroleum cracking olefin products
(01. Izmir Institute of Technology, 2022-12) Arapoğlu, Mehmet Anıl; Artok, Levent
Cracking is a process that long-chain hydrocarbons are broken down into more valuable fragments called naphtha cracking products. The olefins formed as a result of this process have various functions such as forming the smallest building blocks of fine and speciality chemicals. It has been foreseen that borylation processes can be applied as a conversion method of these products into valuable intermediate structures. In this context, this thesis describes first time the transition-metal-catalyzed borylation of a number of petroleum cracking olefin products. Borylation reactions have been extensively investigated in the literature and have become one of the popular methods for synthesizing organoboron reagents, which can also be used in the synthesis of functional materials, pharmaceuticals, and agricultural chemicals. In the context of this thesis, petroleum cracking olefinic products were converted into high-value-added organoboron derivatives by metal-catalysed hydroboration and dehydrogenative borylation methods. For this purpose, the experimental conditions were optimized using propene and isobutene reagents. It has been shown in this study that iridium complexes with N-Heterocarbene (NHC) ligands are highly effective catalysts and therefore anti-Markovnikov hydroboration products can be produced in excellent yields even at very low catalyst loadings. On the other hand, alkenyl boron products could be obtained with high yields, which could be performed in the absence of dehydrogenative borylation reactions, ligand, base, and any other additives. The applicability of these methods in internal and terminal alkenes such as cyclohexene, ethene, decene and styrene has been also demonstrated. Finally, these products were converted into a number of intermediates by Suzuki-Miyaura cross-coupling reactions. Thus, in the conversion of alkenes to valuable intermediates, practical and sustainable applications would be possible by using simple, abundant, and cheap reagents instead of expensive and dangerous chemicals.
Cell selection algorithms for conventional narrow band wireless systems
(Izmir Institute of Technology, 2017-07) Yılmaz, Saadet Simay; Özbek, Berna
Public safety organizations provide a stable and secure environment for the society. Wireless communication between public safety officers is very important to transmit voice or data during an emergency crisis. When the public communication networks can not provide service during crisis, disaster and high traffic cases, Professional Mobile Radio systems (PMR) such as conventional Association of Public Safety Communications Officials (APCO25) and trunked Digital Mobile Radio (DMR) systems are needed to improve the service quality and to provide uninterrupted service provided to the users. While providing continuous voice and data service, it is very important to efficiently select the base station to be served and to ensure that a mobile user can seamlessly attach from one base station to another base station while moving within a cell. In this sense, it is critical to determine the base station to be served by efficient cell selection algorithms. Cell selection is the process of deciding the base station which provides services to the users. Cell selection plays an important role in balancing the system load and thus overall system performance. By means of efficient cell selection algorithms, it is aimed to reduce the waiting time and to connect a base station as soon as possible while establishing reliable transmission link for PMR systems in emergencies.
Changes in protein profiles in Bortezomib applied Multiple Myeloma cells
(Izmir Institute of Technology, 2011) Turan, Taylan; Şanlı Mohamed, Gülşah
Multiple Myeloma is a malignant B-cell neoplasm that is characterized by the accumulation of malignant plasma cells in the bone marrow. Over the recent years, several novel agents have been introduced in the treatment of this disease. Bortezomib is the first of a new class of agents known as proteasome inhibitors. The main objective of the project was basically to both determine the cytotoxic and apoptotic effects of Bortezomib on Multiple Myeloma U-266 cells and compare and explore the differences between Bortezomib applied Multiple Myeloma cells and control group Multiple Myeloma cells, by proteomics studies. In order to achieve our aims in the project, variety of multidisciplinary subjects were come together. Cancer research techniques, biochemical studies at protein level and proteomics were combined in our studies. In this study, our experimental results demonstrated that Bortezomib has antiproliferative and apoptotic effects on MM U-266 cells. On the other hand, the responsible proteins for the effect mechanism of anti-cancer agent on cells were determined by MALDI-TOF-TOF Mass Spectrometry for the first time. According to the mass spectrometric analysis, 37 protein spots were differentially expressed. Among them, five proteins were newly formed, ten proteins lost, twelve proteins were up-regulated and ten proteins were down-regulated as compared to control group (untreated cells).These differential expressed proteins in response to Bortezomib have different important functions ranging from cell signaling transduction, cell cycle regulation, apoptosis to immunity and defense mechanism. In conclusion, it was identified which proteins have a central role behind the effect of Bortezomib on MM U-266 cells. The identified proteins may let to be possible to treat other cancer types by same anticancer agent. The data obtained by this study may also be helpful for medical schools and drug designers and may also provide new treatments.
Characterization and catalytic applications of hydrothermally synthesized poyoxotungstate clusters containing organic-inorganic hybrid materials
(Izmir Institute of Technology, 2019-07) Ece, Özlem; Eanes, Mehtap; Çağır, Ali
Many scientists have been interested in hydrothermal synthesis and characterization of polyoxometalate clusters containing organic-inorganic hybrid materials recently because of having different applications in lots of fields, especially, using as catalysis in chemical reactions. In this study, three novel polyoxotungstate clusters were synthesized using hydrothermal method and catalytic activities of these three novel polyoxometalates and in addition two crystals previously synthesized in our group were studied. The first compound, [(4,4’-bpyH2)3][PCuW11O39] yellow crystals, crystallize in the space group P2(1)/n of the monoclinic system with four formula units in a cell. The crystal is a Keggin polyoxometalate and includes free 4,4’-bipyridine groups between the clusters. The second compound, (4,4’-bpyH2)[H2PW12O40]2.H2O colorless crystals, crystallize in the space group Ia-3 of the cubic system with twelve formula units in a cell. The crystal is a Keggin polyoxometalate and consists of two polyoxotungstate clusters, a free 4,4’-bipyridine group and a water molecule. The third and the last novel compound, (4,4’-bpyH2)4[H2P2W18O62]2 dark yellow crystals, crystallize in the space group P-1 of the triclinic system with four formula units in a cell. The crystal is a Wells-Dawson polyoxometalate and contains two polyoxotungstate clusters and free 4,4’-bipyridine groups between clusters. The catalytic study has been carried out using starch hydrolysis reactions by using hydrothermal synthesis and five different crystals were tried and conversion results were obtained. Starch samples converted to D-glucose with glucose yields above 90 wt.%. Catalyst reusability was performed for each crystal. No appreciable loss was observed in activity after five reaction cycles for each crystal.
Characterization of ion implanted surfaces by laser induced breakdown spectroscopy, LIBS
(01. Izmir Institute of Technology, 2008) Örer, Sabiha; Yalçın, Şerife
Laser Induced Breakdown Spectroscopy, LIBS, is a versatile atomic emission spectrometric technique for the determination of the elemental composition of solids, liquids, gases and aerosols with the need for little or no sample preparation.In this study, an optical LIBS system from its conventional parts was designed, constructed and optimized for spectrochemical analysis of solid materials. Specifically, the 2-D elemental distribution of Ge ions on silicon oxide surfaces, prepared by the method of ion implantation, with differing atomic concentrations between 1016 - 1017 ions/cm2 have been investigated by LIBS. For this purpose a Nd: YAG laser operating at the second harmonic wavelength, 532 nm, was used to create a plasma on the material surfaces. Spatially and temporally resolved atomic emission from the luminous plasma was detected by an Echelle spectroctrograph and Intensified Charged Coupled Device (ICCD) detector combination. Spectral emission intensity from the LIBS measurements has been optimized with respect to time, crater size, ablation depth and laser energy. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-Ray Spectroscopy (EDX) have been utilized to obtain crater depth, morphology and elemental composition of the sample material, respectively. LIBS spectral data revealed the possibility of performing 2-D distribution analysis of Ge ions over the silicon oxide substrate at Ge ion concentrations lower than 0.5% (atomic). LIBS as a fast semi-quantitative analysis method with 50.m lateral and 800 nm depth resolutions has been evaluated. In this wok, elemental analysis of some metal surfaces, such as Al and Cu, was also performed by LIBS.Keywords: LIBS, surface analysis, Ge ion implantation, lateral resolution,

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