Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Ashyralyyev, Charyyar(21)
- Ashyralyev, A.(7)
- Ashyralyev, Allaberen(7)
- Ashyralyyev, C.(6)
- Ashyralyev, A(5)
- Cakir, Zafer(5)
- Akay, K.U.(3)
- Akyuz, Gulzipa(3)
- Cakalli, H.(3)
- Canak, I.(3)
- Dedeturk, Mutlu(3)
- Gurtug, O.(3)
- Harte, R.(3)
- Kandemir, H.S.(3)
- Kocinac, L.D.R.(3)
- Lukashov, A.(3)
- Malkowsky, E(3)
- Sahin, H.(3)
- Tez, M.(3)
- Ucgun, F.C.(3)
- Uyaver, S.(3)
- Akyuz, G.(2)
- Dik, M.(2)
- Emirov, Nazar(2)
- Lukashov, A(2)
- Onvural, O.R.(2)
- Savas, E.(2)
- Sezer, S.A.(2)
- Turkoglu, A.D.(2)
- Akkan, Pinar(1)
- Akkan, Yasar(1)
- Akyel, T.(1)
- Akyüz, Gulzipa(1)
- Al-Hammouri, Ahmad(1)
- Alemdağ, Selçuk(1)
- Altan, Orhan(1)
- Artykov, Merdan(1)
- Atalar, Ilyas(1)
- Ayşe Koç(1)
- Basar, F.(1)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Layered Polymeric Carbon Nitride as a Green Support for Cellulase Immobilization: Improved Stability, Activity, and Reusability
Gulesci, Nuri; Altan, Orhan; Toprak, Ali; Yalçın, M. Serkan; Bilgin, Ramazan; Yildirim, Deniz
Polymeric carbon nitride (PCN) has attracted considerable attention in recent years due to its layered structure and donor groups such as terminal amines and triazine units. In this study, PCN was synthesized from melamine and employed for the first time as a support material for the immobilization of cellulase, a key enzyme used in numerous industrial applications. Transmission electron microscopy (TEM) analysis revealed that ranged from 219 to 375 nm in size, thereby confirming their nanoscale layered morphology. Cellulase from Aspergillus sp. was immobilized onto PCN using three methods. In the first approach, cellulase was adsorbed onto PCN to form PCN@cellulase. In the second method, PCN@cellulase was cross-linked with glutaraldehyde (PCN@cellulase/Glu). Finally, the primary amino group of PCN was modified with glutaraldehyde, and the cellulase was immobilized onto this support via covalent attachment (PCN/Glu@cellulase). Each cellulase preparation was assessed for its optimal pH, temperature conditions, thermal stability, and enzyme kinetics. The optimal pH was 5.5 for all cellulase preparations, while the optimal temperature was 45 °C for free cellulase and 55 °C for all immobilized cellulase preparations. Thermal stability of PCN@cellulase, PCN@cellulase/Glu, and PCN/Glu@cellulase increased by 2.1-, 2.7-, and 3.7-fold, respectively, compared to the free cellulase. PCN/Glu@cellulase showed a 1.4-fold higher catalytic efficiency than the free cellulase and retained 80% of its initial activity after 10 reuses. This work highlights PCN as a green, metal-free, and easy-to-prepare support for enzyme immobilization, thereby opening new possibilities for sustainable bioprocessing applications.
AtıfScopus1WoS1OpenAlex2İncele - MakaleYalnız künye2024Scopus SJRQ3Antioxidant Capacity, Oxidative Stability and Sensory Properties of Flavored Butter Using Dried Apricot Pulp
Bulut, M.; Gundogdu, E.
In this study, various concentrations of Dried Apricot Pulp (DAP) were added to butter at levels of 0, 15, 20, and 25%, and its effects on antioxidant capacity, oxidative stability, color, and sensory attributes were assessed during 45 days of storage. Butter samples were labeled as A0 (Control), A15, A20, and A25 corresponding to the respective levels of DAP incorporation. The addition of DAP resulted in significant reductions in pH, while titratable acidity (expressed as lactic acid %) and free fatty acids (FFA) content (mg KOH g-1 butter) increased in a dose-dependent manner (P< 0.05). Fortification with DAP delayed peroxide formation in the butter samples. Additionally, DAP supplementation significantly (P< 0.05) increased Total Phenolic Content (TPC), improved DPPH (2,2-Diphenyl-1-Picrylhydrazyl) scavenging activity, and increased Total Antioxidant Capacity (TAC) during storage. Panelists assigned higher sensory scores to the DAP-enhanced butters. These fortified butters exhibited lower fat content (ranging from 65.25 to 65.50%) compared to the control butter (73.75%). Notably, the total sugar content of samples A15, A20, and A25 was 3.69±0.06, 4.70±0.06, and 5.64±0.08, respectively. Overall, this study demonstrates the potential of all DAP ratios, particularly 25%, as rich sources of antioxidants. However, further formulation adjustments and comprehensive analyses are warranted for industrial and marketing applications.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ4Evaluation of stability in rock-fill dams by numerical analysis methods: a case study (Gümüşhane-Midi Dam, Türkiye)
Sari, Mahmut
Serious stability issues could arise both during and after construction if the dams’ body designs are not realistically accurate. Engineering studies are therefore crucial for identifying the body’s instability prop-erties in designing the dam body. In this study, horizontal and vertical displacement and stress-deformation analyses were carried out on the body of the Midi Waste Dam located in Karamustafa Village of Gümüşhane Province. In these analyses, the elasticity modulus and Poisson’s ratio of the soil were determined using the seismic method, which is one of the commonly used geophysical methods. The cohesion and internal friction angle of the rock fill were determined by taking into account Leps’ charts. The state of the dam body under the influence of the siltation load and seismic load at the end of operation was shown by applying the finite element method. It was found that there was no instability issue with the researched dam because the safety numbers obtained from the stability study of the dam body were greater than the 1.2 safety number accepted for the stability of the dams (SRF: 2.03, SRF: 1.37). The maximum vertical displacement of the dam body at the foundation base was found as 3.78 cm, the horizontal displacement as 5.80 cm, and the total displacement amount as 6.75 cm when the dam body was examined in terms of displacements. In terms of the statics of the dam body, the vertical, horizontal, and total displacements estimated with the numerical analysis methods did not present a problem, and it was demonstrated that this scenario was also supported by the stability of the body in the applied analyses.
AtıfScopus7WoS7İncele - Yüksek Lisans TeziAçık Erişim2022Bireysel emeklilik sistemi ve makroekonomik istikrar
Ayşe Koç
Günümüz dünya ekonomisinde emeklilik sistemleri, ulusların ekonomik istikrarı sağlamalarında en önemli güvenceleri olmuştur. Nüfusun yaşlanması, aktif-pasif dengesinin bozulması, sağlık hizmetlerinin maliyetlerindeki artış, siyasi müdahaleler, ekonomik dalgalanmalar, enflasyon, işsizlik gibi nedenler, hemen her ülkede sosyal güvenlik sistemlerini sıkıntıya sokmuştur. Oluşan bu krizler neticesinde sosyal güvenliği tamamlayıcı bir unsur olan bireysel emeklilik sistemi, krizlerin çözümü için uygun bir araç olarak görülmüş ve uygulamaya konulmuştur. BES, bireylerin çalışırken yaşadığı refahın emeklilik döneminde de sürdürülmesini amaçlamaktadır. Bu çalışmanın amacı bireysel emeklilik fon büyüklüğü ile makroekonomik istikrar arasındaki nedensellik ilişkisini Türkiye için analiz etmektir. Analiz iki aşamadan oluşmaktadır. Birinci aşamada, GSYH (büyüme), enflasyon, işsizlik, bütçe açığı ve cari işlemler açığı değişkenleri kullanılarak, Temel Bileşenler Analizi ile Türkiye için bir makroekonomik istikrar endeksi oluşturulmuştur. İkinci aşamada Makroekonomik İstikrar Endeksi ile BES fon büyüklüğü arasındaki nedensellik ilişkileri Toda-Yamamoto ve Fourier Toda Yamamoto Nedensellik Testi kullanılarak analiz edilmiştir. Çalışma sonuçları, bireysel emeklilik fon büyüklüğü ile makroekonomik göstergeler arasında nedensellik ilişkisi olmadığını göstermektedir. Çalışmadan elde edilen sonuçlar, geçmiş dönem bireysel emeklilik sistemi fon tutarlarının, makroekonomik istikrar öngörülerinde kullanılamayacağını göstermektedir. Kur oynaklığı ve enerji maliyetlerinde meydana gelen artışlar, COVID 19 nedeniyle küresel tedarik zincirinde meydana gelen bozulmalar, dünya genelinde enflasyon oranlarının artmasına neden olmuş, gelişmiş ülkelerde yüksek enflasyon nedeniyle alınan faiz artırım kararları, diğer gelişmekte olan ülkelerde olduğu gibi Türkiye ekonomisini de olumsuz etkilemiştir. Finansman olanaklarının kısıtlı olması ve yükselen kurlar ülke genelinde kırılganlığı artırmaktadır. Bu bağlamda, makroekonomik istikrarın sağlanabilmesi için, finansal kırılganlıkların azaltılması ve istikrarlı bir büyümenin sağlanması önemlidir.
- MakaleYalnız künye2022Scopus SJRQ2On the Stability of Parabolic Differential and Difference Equations with a Time-Nonlocal Condition
Ashyralyev, A.; Ashyralyyev, C.
Abstract: In this paper, we study the integral type of the time-nonlocal boundary value problem for a parabolic equation. The well-posedness of these differential and difference problems in Hölder spaces is established. Numerical illustrations in a test case are presented.
AtıfScopus6WoS6OpenAlex8İncele - MakaleAçık Erişim2021On fourth order accuracy stable difference scheme for a multi-point overdetermined elliptic problem
Ashyralyyev, C.; Akyuz, G.
In this paper fourth order of accuracy difference scheme for approximate solution of a multi-point elliptic overdetermined problem in a Hilbert space is proposed. The existence and uniqueness of the solution of the difference scheme are obtained by using the functional operator approach. Stability, almost coercive stability, and coercive stability estimates for the solution of difference scheme are established. These theoretical results can be applied to construct a stable highly accurate difference scheme for approximate solution of multi point overdetermined boundary value problem for multidimensional elliptic partial differential equations.
AtıfOpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ2On the absolute stable difference scheme for the space-wise dependent source identification problem for elliptic-telegraph equation
Ashyralyev, Allaberen; Al-Hammouri, Ahmad; Ashyralyyev, Charyyar
The present paper is devoted to study the first order of accuracy absolute stable difference scheme for the approximate solution of the space identification problem for the elliptic-telegraph equation in Hilbert spaces with the self-adjoint positive definite operator. The main theorem on the stability of the difference scheme is established. In applications, theorems on the stability of difference schemes for two types of the space identification problems for multidimensional elliptic-telegraph partial differential equations are proved. Numerical analysis is provided.
AtıfScopus27WoS13OpenAlex23İncele - BildiriYalnız künye2021Stability estimates for a third order of accuracy difference scheme elliptic overdetermined multi-point problem
Ashyralyyev, Charyyar; Akyuz, Gulzipa; Cakalli, H.; Kocinac, L.D.R.; Ashyralyev, A.; Harte, R.; Dik, M.; Canak, I.; Kandemir, H.S.; Tez, M.
In this work, we discuss a third order of accuracy difference scheme for approximate solution of the elliptic overdetermined multi-point problem in the Hilbert space. Functional operator approach is used to study existence and uniqueness of solution of difference problem. Stability, almost coercive stability and coercive stability estimates for solution of difference scheme are established.
- MakaleAçık Erişim2021On fourth order accuracy stable difference scheme for a multi-point overdetermined elliptic problem; [Көпнүктелi қайтаанықталған эллипстiк есеп үшiн төртiншi реттi дәлдiктi тұрақтылық айырымдық схемасы туралы]; [Об устойчивой разностной схеме четвертого порядка точности для многоточечной переопределенной эллиптической задачи]
Ashyralyyev, C.; Akyuz, G.
In this paper fourth order of accuracy difference scheme for approximate solution of a multi-point elliptic overdetermined problem in a Hilbert space is proposed. The existence and uniqueness of the solution of the difference scheme are obtained by using the functional operator approach. Stability, almost coercive stability, and coercive stability estimates for the solution of difference scheme are established. These theoretical results can be applied to construct a stable highly accurate difference scheme for approximate solution of multipoint overdetermined boundary value problem for multidimensional elliptic partial differential equations.
AtıfOpenAlex5İncele - BildiriYayıncıda açık erişim2021On stable difference scheme for identification elliptic problem with integral and second kind boundary condition
Ashyralyyev, Charyyar; Cakalli, H.; Kocinac, L.D.R.; Ashyralyev, A.; Harte, R.; Dik, M.; Canak, I.; Kandemir, H.S.; Tez, M.; Gurtug, O.
In this study, the first order of accuracy difference scheme for approximate solution of source identification elliptic problem with integral and second kind boundary conditions is considered. Stability and coercive stability estimates for solution of the difference scheme are described. Moreover, test example with computation results is given.
- MakaleYalnız künye2020Scopus SJRQ2Source Identification Problem for a Parabolic Equation with Multipoint Nonlocal Boundary Condition
Ashyralyyev, Charyyar; Akkan, Pinar
We study a source identification problem for a parabolic equation with multipoint nonlocal boundary condition. Stability estimates for the solution of abstract source identification problem are established. In application, stability estimates for the solution of the overdetermined mixed boundary value problem for multidimensional parabolic equation are obtained. The first and second order of accuracy difference schemes for the approximate solution of this problem are constructed. Stability estimates for solutions of these difference schemes are proved. Numerical illustration for a simple test problem is presented.
AtıfScopus7WoS6OpenAlex7İncele - MakaleYalnız künye2020Scopus SJRQ1Stability of Rothe difference scheme for the reverse parabolic problem with integral boundary condition
Ashyralyyev, Charyyar
In this paper, we study the approximation of reverse parabolic problem with integral boundary condition. The Rothe difference scheme for an approximate solution of reverse problem is discussed. We establish stability and coercive stability estimates for the solution of the Rothe difference scheme. In sequel, we investigate the first order of accuracy difference scheme for approximation of boundary value problem for multidimensional reverse parabolic equation and obtain stability estimates for its solution. Finally, we give numerical results together with an explanation on the realization in one- and two-dimensional test examples.
AtıfScopus9WoS6OpenAlex9İncele - MakaleAçık Erişim2020Numerical solution to elliptic inverse problem with Neumann-type integral condition and overdetermination; [Интегралдық шарты бар және қайта анықталған Нейман типтi эллипстiк керi есептiң сандық есептеуi]; [Численное решение эллиптической обратной задачи с интегральным условием и переопределением типа Неймана]
Ashyralyyev, C.; Cay, A.
In modeling various real processes, an important role is played by methods of solution source identification problem for partial differential equation. The current paper is devoted to approximate of elliptic over determined problem with integral condition for derivatives. In the beginning, inverse problem is reduced to some auxiliary nonlocal boundary value problem with integral boundary condition for derivatives. The parameter of equation is defined after solving that auxiliary nonlocal problem. The second order of accuracy difference scheme for approximately solving abstract elliptic overdetermined problem is proposed. By using operator approach existence of solution difference problem is proved. For solution of constructed difference scheme stability and coercive stability estimates are established. Later, obtained abstract results are applied to get stability estimates for solution Neumann-type overdetermined elliptic multidimensional difference problems with integral conditions. Finally, by using MATLAB program, we present numerical results for two dimensional and three dimensional test examples with short explanation on realization on computer.
AtıfScopus7WoS6OpenAlex9İncele - MakaleAçık Erişim2020Scopus SJRQ1Effect of ultrasonication treatment on structural, physicochemical and bioactive properties of pasteurized rosehip (Rosa canina L.) nectar
Atalar, Ilyas; Saricaoglu, Furkan T.; Odabas, Halil I.; Yilmaz, Volkan A.; Gul, Osman
The effect of ultrasonication process (US) on the physical and bioactive properties of pasteurized rosehip nectar was investigated. In order to solve sedimentation problem, two amplitude levels (50 and 100%) and different treatment times (5, 10, 15 and 30 min) were applied to rosehip nectars. Mean particle size decreased as amplitude and treatment time increased. US treatment caused to increase in redness and yellowness values of nectars and also color change was found noticeable as 1.9-2.6 at 100% amplitudes. US treated samples showed no sedimentation during storage for 15 days while control sample displayed 74% colloidal stability. All samples showed shear-thinning behavior and were characterized as weak gel network. Total phenolic and carotenoid contents and antioxidant activity was increased by US treatment, however, ascorbic acid content decreased. US treatment can be an alternative technology preventing sedimentation problems during shelf life with minimally affecting bioactive and physical properties of rosehip nectar.
AtıfScopus19WoS12OpenAlex20İncele - Yüksek Lisans TeziAçık Erişim2019Genişletilmiş tümör-bağışıklık gözetimi modelinin deterministik ve stokastik analizi
Semih Çelenkli
Bu tez çalışmasında daha önce tanımlanmış olan deterministik tümör hücresi bağışıklık gözetim modelleri incelenmiş bu modellerin temel bileşenleri tek tek tanımlanarak bilimsel literatüre uygun, yeni bir tümör hücresi-bağışıklık gözetim modeli oluşturulmuştur. Kinetik analiz yöntemiyle oluşturulan bu modelin temelinde, bağışıklık gözetiminden kaçan tümör hücrelerinin ve herhangi bir kaçma mekanizması geliştiremeyen tümör hücrelerinin (saf tümör hücreleri) zaman içerisinde göstermiş oldukları gelişim incelenmektedir. Bağışıklık gözetiminden kaçan tümör hücreleri vahşi tümör hücresi olarak adlandırılmıştır. Öncelikle tümör hücrelerinin bağışıklık gözetiminden kaçmadığı varsayılarak saf tümör hücresi bağışıklık gözetim modeli tanımlanmıştır. Bu modelin biyolojik olarak anlamlı olabilmesi için model değişkenlerinin pozitif ve sınırlı olduğu durumlar incelenmiştir. Saf tümör hücresi modeline bağlı olarak yazılan denklem sisteminin denge noktaları bulunmuş, tümörsüz denge noktasının temel üreme sayısı bulunarak tümörsüz denge noktasındaki asimptotik kararlılık ve global kararlılık durumları incelenmiştir. Diferansiyel denklem sisteminde tümör hücresi ile bağışıklık etkileşimi sonucunda tanımlanan parametreler, normal dağılım ve genelleştirilmiş beta dağılımı altında rastgele etki terimleri ile yeniden tanımlanmış ve elde edilen rastgele etkileşim modeli ile tümör hücresi bağışıklık etkileşim süreci incelenmiştir. Ayrıca deterministik ve rastgele modeller için elde edilen sonuçlar, stokastik etki sonucunda elde edilen modelin sonuçları ile karşılaştırılarak modelin yorumlanması sağlanmıştır. Son olarak, bağışıklık hücrelerinden tümör kaçışı öngörülerek vahşi tümör hücresi bağışıklık gözetimi modeli oluşturulmuş ve model bilimsel varsayımlara dayalı olarak modellenen parametreler kapsamında incelenerek yorumlanmıştır.
- BildiriAçık Erişim2019Numerical solution of Neumann type elliptic overdetermined multipoint mixed boundary value problem
Ashyralyyev, Charyyar; Karabey, Suzan; Cakalli, H.; Kocinac, L.D.R.; Harte, R.; Cavalcanti, V.N.D.; Ashyralyev, A.; Sakalli, I.; Canak, I.; Gurtug, O.
In the present paper, Neumann type elliptic overdetermined multipoint boundary value problem is discussed. The first and second order of accuracy difference schemes (ADSs) for the numerical solution of elliptic overdetermined multipoint boundary value problems are presented. Stability estimates for solutions of difference schemes are obtained. Numerical results for mixed boundary value problem are given.
- MakaleYayıncıda açık erişim2018Scopus SJRQ2Finite difference method for bitsadze-samarskii type overdetermined elliptic problem with dirichlet conditions
Ashyralyyev, Charyyar; Akyuz, Gulzipa
In this paper, we apply finite difference method to Bitsadze-Samarskii type overdetermined elliptic problem with Dirichlet conditions. Stability, coercive stability inequalities for solution of the first and second order of accuracy difference schemes (ADSs) are proved. Then, established abstract results are applied to get stable difference schemes for Bitsadze-Samarskii type overdetermined elliptic multidimensional differential problems with multipoint nonlocal boundary conditions. Finally, numerical results with explanation on the realization in two dimensional and three dimensional cases are presented.
AtıfScopus10WoS7OpenAlex11İncele - MakaleAçık Erişim2017Scopus SJRQ3A fourth order approximation of the neumann type overdetermined elliptic problem
Ashyralyyev, Charyyar
In this paper, we consider an inverse elliptic problem with Neumann type overdetermination and construct a fourth order of accuracy difference scheme for its solution. Stability, almost coercive stability and coercive stability estimates for the solution of difference problem are proved. Later, we construct a fourth order difference scheme for an inverse problem for multidimensional elliptic equation with Neumann type overdetermination and Dirichlet boundary condition. Finally, we illustrate numerical example with descriptions of numeric realization in a two-dimensional case.
AtıfScopus19WoS12OpenAlex17İncele - MakaleYalnız künye2017Scopus SJRQ3Approximate solution for an inverse problem of multidimensional elliptic equation with multipoint nonlocal and neumann boundary conditions
Ashyralyyev, Charyyar; Akyuz, Gulzipa; Dedeturk, Mutlu
In this work, we consider an inverse elliptic problem with Bitsadze-Samarskii type multipoint nonlocal and Neumann boundary conditions. We construct the first and second order of accuracy difference schemes (ADSs) for problem considered. We stablish stability and coercive stability estimates for solutions of these difference schemes. Also, we give numerical results for overdetermined elliptic problem with multipoint Bitsadze-Samarskii type nonlocal and Neumann boundary conditions in two and three dimensional test examples. Numerical results are carried out by MATLAB program and brief explanation on the realization of algorithm is given.
AtıfScopus22WoS19İncele - MakaleAçık Erişim2017Scopus SJRQ3Numerical solution to Bitsadze-Samarskii type elliptic overdetermined multipoint NBVP
Ashyralyyev, Charyyar
This paper is devoted to a Bitsadze-Samarskii type overdetermined multipoint nonlocal boundary value problem (NBVP). This inverse problem is reduced to an auxiliary multipoint NBVP. Stability estimates for the solution of the auxiliary NBVP are established. The finite difference method is applied to get the first and second order of accuracy of approximate solutions of the abstract overdetermined problem. Stability estimates for the solution of difference problems are proved. Then the established abstract results are applied to get stability estimates for the solution of the Bitsadze-Samarskii type overdetermined elliptic multidimensional differential and difference problems with multipoint nonlocal boundary conditions (NBVC). Finally, numerical results with explanation on the realization for two dimensional and three dimensional elliptic overdetermined multipoint NBVPs in test examples are presented.
AtıfScopus30WoS23OpenAlex27İncele