Mühendislik Bilimleri Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/36

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Geography of irreducible plane sextics
(Oxford University Press, 2015) Akyol, Ayşegül; Degtyarev, Alex; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Akyol, Ayşegül
We complete the equisingular deformation classification of irreducible singular plane sextic curves. As a by-product, we also compute the fundamental groups of the complement of all but a few maximizing sextics.
Glucose-dependent anaplerosis in cancer cells is required for cellular redox balance in the absence of glutamine
(NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND, 2016) Cetinbas, Naniye Malli; Sudderth, Jessica; Harris, Robert C.; Cebeci, Aysun; Negri, Gian L.; Yilmaz, Oemer H.; DeBerardinis, Ralph J.; Sorensen, Poul H.; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü;
Cancer cells have altered metabolism compared to normal cells, including dependence on glutamine (GLN) for survival, known as GLN addiction. However, some cancer cell lines do not require GLN for survival and the basis for this discrepancy is not well understood. GLN is a precursor for antioxidants such as glutathione (GSH) and NADPH, and GLN deprivation is therefore predicted to deplete antioxidants and increase reactive oxygen species (ROS). Using diverse human cancer cell lines we show that this occurs only in cells that rely on GLN for survival. Thus, the preference for GLN as a dominant antioxidant source defines GLN addiction. We show that despite increased glucose uptake, GLN addicted cells do not metabolize glucose via the TCA cycle when GLN is depleted, as revealed by C-13-glucose labeling. In contrast, GLN independent cells can compensate by diverting glucose-derived pyruvate into the TCA cycle. GLN addicted cells exhibit reduced PDH activity, increased PDK1 expression, and PDK inhibition partially rescues GLN starvation-induced ROS and cell death. Finally, we show that combining GLN starvation with pro-oxidants selectively kills GLN addicted cells. These data highlight a major role for GLN in maintaining redox balance in cancer cells that lack glucose-dependent anaplerosis.
Near- and Far-Field Characterization of Planar mm-Wave Antenna Arrays with Waveguide-to-Microstrip Transition
(SPRINGERONE NEW YORK PLAZA, SUITE 4600 , NEW YORK, NY 10004, UNITED STATES, 2016) Salhi, Mohammed Adnan; Kazemipour, Alireza; Gentille, Gennaro; Spirito, Marco; Kleine-Ostmann, Thomas; Schrader, Thorsten; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Kazemipour, Alireza
We present the design and characterization of planar mm-wave patch antenna arrays with waveguide-to-microstrip transition using both near- and far-field methods. The arrays were designed for metrological assessment of error sources in antenna measurement. One antenna was designed for the automotive radar frequency range at 77 GHz, while another was designed for the frequency of 94 GHz, which is used, e.g., for imaging radar applications. In addition to the antennas, a simple transition from rectangular waveguide WR-10 to planar microstrip line on Rogers 3003 (TM) substrate has been designed based on probe coupling. For determination of the far-field radiation pattern of the antennas, we compare results from two different measurement methods to simulations. Both a far-field antenna measurement system and a planar near-field scanner with near-to-far-field transformation were used to determine the antenna diagrams. The fabricated antennas achieve a good matching and a good agreement between measured and simulated antenna diagrams. The results also show that the far-field scanner achieves more accurate measurement results with regard to simulations than the near-field scanner. The far-field antenna scanning system is built for metrological assessment and antenna calibration. The antennas are the first which were designed to be tested with the measurement system.
ILGIN LİNYİT İŞLETMELERİ GÖLETLERİNDE ASİT MADEN DRENAJI VE REHABİLİTASYONU
(Niğde Ömer Halisdemir Üniversitesi, 2016) Delibalta,Mahmut Suat; Uzal, Niğmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Uzal, Niğmet
Maden yataklarının aranması, üretimi ve zenginleştirilmesi süreçlerinde uygulanan işlemler; hava, toprak, sukaynaklarını, dolayısıyla çevreyi ve çevrede yaşayan canlıları etkilemektedir. Genel olarak kömür açık işletmemadenciliğinin çevre üzerindeki olumsuz etkileri, yeraltı madenciliği ve cevher hazırlama çalışmalarına oranlaçok daha fazladır.Kömür açık işletmeleri sonrası oluşan üretim çukurlarının dekapaj malzemesiyle doldurulmaması halinde,yüzey suları ve yeraltı su seviyesinin yükselmesi ile küçük veya büyük göletler oluşmaktadır. Düşük pH değeri(asidik karakteristik) ve yüksek metal konsantrasyonu (Al, Ca, Mn, Fe, Cu, Zn, Pb) içeren bu göletlerde, baskınhalde bulunabilen sülfürlü mineraller ve atık malzemeler en önemli çevresel sorunlardan birini oluşturmaktadır.Bu çalışmada, TKİ GLİ Ilgın linyit işletmeleri 5 farklı gölette su karakterizasyonu izlemeleri yapılarak;ortalama pH 6,49-7,81, bulanıklık (NTU) 0,12-63,6, sülfat içeriği 0,05-2,67 mg SO4/L, kimyasal oksijen ihtiyacı4-136 mg O2/L, elektriksel iletkenlik 285 µS/cm-4,68 mS/cm değerleri ve 1839 ppb Mn, 9777 ppb Fe ile enyüksek ağır metal içerikleri tespit edilmiştir. Saha örneklerine ilişkin analizler üç aylık periyotlarla takipedilmiştir. Belirlenen sonuçlar ilgili yasal yönetmelikler çerçevesinde değerlendirilmiştir.
Magnetic-particle based signal amplification method integrated with mobile-devices for low cost biosensing
(ELSEVIER SCIENCE BV, SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2017) Mzava, Omary; Tas, Zehra; Lafci, Vahit Can; Cakar, Mehmet Akif; Ozdur, Ibrahim; Icoz, Kutay; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü;
We present a signal amplification method for biosensing applications using magnetic particles. In this method, mobile devices and simple spherical glass beads are used as a low-cost microscope to detect magnetic particles. Magnetic particles have two main functions; 1) conventionally capture, separate and transport target molecules 2) form magnetic dipoles under an applied external magnetic field to attract other magnetized particles. When magnetic particles accumulate and form a cluster, the corresponding pixel area in the image taken by the simple microscope is increased resulting in signal amplification. Current focus of new generation biosensor research is to increase the sensitivity levels of the devices to compete with current lab analysis tools while inherently having other advantages such as being low-cost, portable and simple. Biosensors based on micro/nano magnetic particles use various measurement techniques and amplification methods. In order to fully benefit from the advantages of micro/nano technology based systems, measurement set up must be also portable and have high sensitivity. Mobile devices and applications are taking place in medical fields and have high potential for future. In this work mobile devices are employed as measurement setups for the magnetic particle based sensing and signal amplification. The amplification method is not based on bimolecular binding thus cost efficient. After the images of the magnetic particles are taken, these images are sent to cloud computing for analysis by the mobile device. Matlab codes run on cloud servers for processing the images. Finally results are received and displayed on the mobile device. The mobile device based imaging system is able to detect 7 mu m size particles within a 1500 mu m x1500 mu m area and magnetic bead accumulation resulted in at least 5-fold signal amplification. The applied magnetic field is approximately 15 mT and the cost of the system excluding mobile device is under 20 cents. The method is promising for immunomagnetic bead assisted biosensors. (c) 2016 The Authors. Published by Elsevier Ltd.
Preface of the Symposium on: "advances in Analytical, Analytical Approximate, Numerical and Asymptotic Analysis of Sturm-Liouville Problems with the Applications in Engineering"
(American Institute of Physics Inc., 2017) Atay, Mehmet Tarik; Erdogan, Hakan; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Atay, Mehmet Tarik
Preface of the Symposium on: "advances in Analytical, Analytical Approximate, Numerical and Asymptotic Analysis of Sturm-Liouville Problems with the Applications in Engineering"
DETERMINATION OF 1/V-T (P, CONSTANT) DIAGRAMS OF HYDROGEN GASES BY GRAPH-ANALYTICAL METHODS
(YILDIZ TECHNICAL UNIV, YILDIZ CAMPUS, BESIKTAS, ISTANBUL, 34349, TURKEY, 2017) Ibrahimoglu, Beycan; Kanbes Dindar, Cigdem; Erol, Hazal; Karasari, Salih; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü;
Graph-analytical methods provide more accurate results in the analysis of V-T (P=constant) and 1/V-T (P=constant) diagrams of gases. In this study, as a continuation of [1, 2]*, the behavior of hydrogen gas was examined by using graph-analytical method under consideration of volume and density parameters at high pressure and temperature. In this paper, graph-analytical method was applied to draw and examine V-T (P=constant) and 1/V-P (T=constant) diagrams which were based on experimental data of hydrogen and other gases (Hydrogen, carbon dioxide, oxygen, argon, helium, neon, xenon and other gases) at high pressure and temperature. The results indicate that the behavior of hydrogen gas is different from the other gases.
Preface of Mini Symposia of 82-Statistical Methods and Applications in Engineering
(American Institute of Physics Inc., 2018) Greenacre, Zerrin Aşan; Atay, Mehmet Tarık; Gazeloǧlu, Cengiz; 0000-0002-8222-3384; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Atay, Mehmet Tarık; Gazeloǧlu, Cengiz
Preface of Mini Symposia of 82-Statistical Methods and Applications in Engineering
Organic semiconductor based surface-enhanced Raman spectroscopy platforms
(AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2018) Demirel, Gokhan; Usta, Hakan; Facchetti, Antonio; 0000-0002-9778-917X; 0000-0002-0618-1979; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü
Conference Conference: 256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond Location: Boston, MA Date: AUG 19-23, 2018 Sponsor(s):Amer Chem Soc
Performance analysis of photonic lantern based coherent receivers
(NATL INST OPTOELECTRONICS, 1 ATOMISTILOR ST, PO BOX MG-5, BUCHAREST-MAGURELE 76900, ROMANIA, 2018) Oran, A.; Ozdur, I.; 0000-0001-6452-0804; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü
In this paper, we present the simulation results for bit-error-rate improvements of photonic lantern based coherent LIDAR systems. Our results show that using a 19-port photonic lantern, the bit-error-rate can be improved to 0.06 from 0.30 for a range of 100 meters, corresponds to a detection rate improvement from 70% to 94%.
RINGS WITH VARIATIONS OF FLAT COVERS
(HONAM MATHEMATICAL SOC, DEPT MATHEMATICS, COLL NATURAL SCIENCE, CHOSUN UNIV, 309, PILMUN-DAERO, DONG-GU, GWANGJU, 501-759, SOUTH KOREA, 2019) Demirci, Yilmaz Mehmet; Turkmen, Ergul; 0000-0003-3802-4211; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü
We introduce flat e-covers of modules and define e-perfect rings as a generalization of perfect rings. We prove that a ring is right perfect if and only if it is semilocal and right e-perfect which generalizes a result due to N. Ding and J. Chen. Moreover, in the light of the fact that a ring R is right perfect if and only if flat covers of any R-module are projective covers, we study on the rings over which flat covers of modules are (generalized) locally projective covers, and obtain some characterizations of (semi) perfect, A-perfect and B-perfect rings.
Rings with modules having a restricted injectivity domain
(SPRINGER INTERNATIONAL PUBLISHING AG, GEWERBESTRASSE 11, CHAM, CH-6330, SWITZERLAND, 2019) Demirci, Yilmaz Mehmet; Turkmen, Burcu Nisanci; Turkmen, Ergul; 0000-0003-3802-4211; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü
We introduce modules whose injectivity domains are contained in the class of modules with zero radical and call them working-class. This notion gives a generalization of poor modules that have minimal injectivity domain. Semisimple working-class modules always exist for arbitrary rings whereas their predecessors do not. We investigate the rings over which every module is either injective or working-class. Right weakly V-rings are examples of these rings. Moreover, we study the existence of working-class simple modules and show that if there is a projective working-class simple right module, then the ring is a right GV-ring.
Tailored Synthesis of Iron Oxide Nanocrystals for Formation of Cuboid Mesocrystals
(AMER CHEMICAL SOC1155 16TH ST, NW, WASHINGTON, DC 20036, 2021) Soran-Erdem, Zeliha; Sharma, Vijay Kumar; Hernandez-Martinez, Pedro Ludwig; Demir, Hilmi Volkan; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Soran-Erdem, Zeliha
In this work, we systematically studied the shape- and size-controlled monodisperse synthesis of iron oxide nanocrystals (IONCs) for their use as building blocks in the formation of mesocrystals. For this aim, on understanding the influence of the oleic acid concentration, iron-oleate concentration, and heating rate on the synthesis of robust and reproducible IONCs with desired sizes and shapes, we synthesized highly monodisperse similar to 11 nm sized nanocubes and nanospheres. Magnetic measurements of both cubic and spherical IONCs revealed the presence of mixed paramagnetic and superparamagnetic phases in these nanocrystals. Moreover, we observed that the magnetic moments of the nanocubes are more substantial compared to their spherical counterparts. We then demonstrated a simple magnetic-field-assisted assembly of nanocubes into three-dimensional (3D) cuboid mesocrystals while nanospheres did not form any mesocrystals. These findings indicate that small cubic nanocrystals hold great promise as potential building blocks of 3D magnetic hierarchical structures with their superior magnetic properties and mesocrystal assembly capability, which may have high relevance in various fields ranging from high-density data storage to biomedical applications.
A Laser-Assisted Cellular Electrophysiology Measurement System
(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC445 HOES LANE, PISCATAWAY, NJ 08855-4141, 2021) Seymen, A. A.; Ozgur, E.; Soran-Erdem, Z.; Ortac, B.; 0000-0001-7607-9286; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Soran-, Erdem, Z.
Patch-clamp technique is the gold standard for cellular electrophysiological measurements, which is capable of measuring single ion transport events across the cell membrane. However, the measurement possesses significant complexities, and it requires a high level of expertise, while its experimental throughput is nevertheless considerably low. Here, we suggest and experimentally demonstrate a laser-assisted method for performing cellular electrophysiological measurements. Femtosecond laser pulses, coupled to an optical microscope, are used to form a sub-micrometer hole on a thin polymer membrane separating two electrodes, where a nearby cell is subsequently placed onto the hole by negative pressure. Afterwards, the cell is punctured using subsequent laser exposure, revealing the cell membrane over the hole for electrophysiological recording. This system could be used to increase the output amount of the electrophysiological measurements substantially.
Investigations of Electrical Resistivity and Thermal Conductivity Dependences on Growth Rate in the Al-Cu-Ti Eutectic Alloy
(SPRINGER/PLENUM PUBLISHERS233 SPRING ST, NEW YORK, NY 10013, 2021) Marasli, Necmettin; Bayram, Umit; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Bayram, Umit
Directional solidification of Al-Cu-Ti (Al-33wt%Cu-0.1wt%Ti) eutectic alloy was done with a growth rate range (V = 8.58 to 2038.65 mu m.s(-1)) at a temperature gradient of 6.45 K.mm(-1) using Bridgman-type directional solidification furnace. The measurements of thermal conductivity (K) and electrical resistivity (rho) for the Al-Cu-Ti alloy solidified with the different values of V were made by the longitudinal heat flow method (LHFM) and DC four-point probe technique (FPPT). While the highest values of K and rho were determined to be 236.04 W.K-1.m(-1) and 5.91 x 10(-8) omega m, respectively, at 8.58 mu m.s(-1), the lowest values of K and rho were obtained to be 199.82 W.K-1.m(-1) and 12.11 x 10(-8) omega m, respectively, at 2038.65 mu m.s(-1). The K and rho dependences on V were obtained to be K=259.96xV(-0.032) and rho=4.47x10(-8)V(0.13) from linear regression analysis. The fusion enthalpy ( increment H) and specific heat difference between solid and liquid ( increment C-P) for the Al-Cu-Ti were also determined to be 222.69 J.g(-1) and 0.266 Jg(-1).K-1, respectively, by means of differential scanning calorimetry (DSC).
Assessment of biocompatibility of novel TiTaHf-based high entropy alloys for utility in orthopedic implants
(ELSEVIER SCIENCE SAPO BOX 564, 1001 LAUSANNE, SWITZERLAND, 2021) Gurel, S.; Nazarahari, A.; Canadinc, D.; Cabuk, H.; Bal, B.; AGÜ, Mühendislik Fakültesi, Makine Mühendisliği Bölümü; Bal, B.
This paper presents the findings of experimentally observed corrosion response of novel TiTaHf-based high entropy alloys (HEAs) in fetal bovine serum (FBS) to evaluate their biocompatibility in presence of proteins and potential to be used as implant materials. Particularly, TiTaHfNb, TiTaHfNbZr and TiTaHfMoZr HEAs were subjected to static immersion experiments in FBS media, and both the HEA samples and the immersion fluids underwent thorough characterization. The findings presented herein show that Zr and Mo addition to the TiTaHf solid solution increased the total ion release from the resulting HEAs in FBS, while the TiTaHfNb HEA became prominent in terms of biocompatibility owing to the reduced ion release in FBS. Moreover, hydroxy apatite (HA) formation was evident on the surfaces of all three HEAs upon immersion in FBS, indicating the potential of the three TiTaHf-based HEAs to form desired binding with the human bone. Considering the fact that passive oxide layer formation facilitating lower susceptibility to corrosion in long-term applications was also observed in the studied HEAs, further elaboration on their mechanical and biological responses is warranted for the sake of a comprehensive assessment regarding their utility as orthopedic implant materials.
WSA-Supplements and Proper Classes
(MDPIST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2022) Demirci, Yilmaz Mehmet; Turkmen, Ergul; 0000-0003-3802-4211; 0000-0002-7082-1176; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Demirci, Mehmet Yılmaz
In this paper, we introduce the concept of wsa-supplements and investigate the objects of the class of short exact sequences determined by wsa-supplement submodules, where a submodule U of a module M is called a wsa-supplement in M if there is a submodule V of M with U + V = M and U ∩ V is weakly semiartinian. We prove that a module M is weakly semiartinian if and only if every submodule of M is a wsa-supplement in M. We introduce CC-rings as a generalization of C-rings and show that a ring is a right CC-ring if and only if every singular right module has a crumbling submodule. The class of all short exact sequences determined by wsa-supplement submodules is shown to be a proper class which is both injectively and co-injectively generated. We investigate the homological objects of this proper class along with its relation to CC-rings.
Analysis of the motion of a rigid rod on a circular surface using interpolated variational iteration method
(YILDIZ TECHNICAL UNIV, 2022) Coskun, Safa Bozkurt; Senturk, Erman; Atay, Mehmet Tarik; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Atay, Mehmet Tarik
In this paper, interpolated variational iteration method (IVIM) is applied to investigate the vibration period and steady-state response for the motion of rigid rod rocking back and forth on a circular surface without slipping. The problem can be considered as a strongly nonlinear oscillator. In this solution procedure, analytical variational iteration technique is utilized by evaluating the integrals numerically. The approximate analytical results produced by the presented method are compared with the other existing solutions available in the literature. The advantage of using numerical evaluation of integrals, the method becomes fast convergent and a highly accurate solution can be obtained within seconds. The authors believe that the presented technique has potentially wide application in the other nonlinear oscillation problems.
On rings with one middle class of injectivity domains
(UNIV OSIJEK, DEPT MATHEMATICSUNIV OSIJEK, DEPT MATHEMATICS, TRG LJUDEVITA GAJA 6, OSIJEK HR-31000, CROATIA, 2022) Demirci, Yilmaz Mehmet; Alizade, Rafail; Turkmen, Burcu Nisanci; Turkmen, Ergul; 0000-0003-3802-4211; 0000-0003-4444-9136; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Demirci, Yilmaz Mehmet
A module M is said to be modest if the injectivity domain of M is the class of all crumbling modules. In this paper, we investigate the basic properties of modest modules. We provide characterizations of some classes of rings using modest modules. In particular, we show that a ring having the class of crumbling modules as the only right middle class of injectivity domains is either a right V-ring or right Noetherian; and a commutative ring with this property is regular. We also give criteria for a ring having the class of crumbling modules as the only right middle class of injectivity domains.
On a class of Harada rings
(DE GRUYTER POLAND SP Z O O, 2022) Türkmen Nişancı, Burcu; Demirci, Yilmaz Mehmet; 0000-0003-3802-4211; AGÜ, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü; Demirci, Yılmaz Mehmet
In this study, inspired by the definition and a previous study [F. Eryilmaz, SS -lifting modules and rings, Miskolc Math. Notes 22 (2021), no. 2, 655-662], left Harada rings are adapted to ss-Harada rings, and the important properties of these rings are provided. The characterization of a left ss-Harada ring R with R left perfect and Rad(R) included in Soc(RR) was found with the help of strongly local R-modules.

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