Geochemistry and geochronology of Middle Eocene subduction-related felsic volcanics in the Misis-Andirin Complex of the Southeast Anatolian Orogenic Belt

Nusret Nurlu,Ahmet Can Akinci,Milan Kohút 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.6

LA-ICP-MS zircon geochronology and geochemistry (whole-rock & mineral chemistry) from the Misis-Andirin Complex (MAC) volcanic rocks are reported. The MAC records magmatic, sedimentary, and tectonic processes operating at the northern active margin of the Neotethys (South Tethys) in the eastern Mediterranean district. The MAC represents an association of an originally active continental margin including the Engizek (in the NE), Andirin (central) and Misis (in the SW) segments. The felsic extrusives are depleted in HFSE (high-field-strength elements), enriched in LILE (large-ion lithophile elements) and have flat-type REE patterns; these trends and also biotite chemistry verify their supra-subduction zone tectonic environment. The studied volcanic unit consists of mainly rhyolite, dacite and rare andesite rocks, and is intercalated with Bulgurkaya Formation. These felsic extrusive rocks show relative depletions in Ti + Nb, and partial enrichment in Cs, Rb, Ba, and Th in the N-MORB (normal-mid ocean ridge basalt) normalized spider plot, suggesting their derivation from a supra-subduction geodynamic environment. The La/Nb (1.92–2.33) and Nb/Th (1.0–1.12) ratios of all the analysed extrusives from Andirin region present arc magmas or volcanic rocks affinity that could have been contributed by crustal source contents and also examined volcanics yield nearly flat Ba/La ratios with relatively increasing Th/Yb, suggesting the contribution of sediments or crustal contamination. The Al-in-hornblende thermobarometry (2.04 to 1.55 kbar) of Mg-Fe hornblende in the volcanics of the MAC represents their crystallization of amphibole in the moderate to shallow crustal level at a maximum 6.7 km to a minimum 5.1 km depth. The ilmenite-magnetite thermometer based on Fe-Ti oxide equilibria shows that the Andirin region felsic magmas were at 717℃ and at an ƒO2 of approximately 2.16 log units (+1.51 NNO). The MAC extrusive volcanic rocks were produced throughout the Eocene period, and our new U-Pb zircon dating (47.13 ± 0.5 Ma) confirmed mainly younger Lutetian age of the volcanic activity in the Andirin area.

Petrology and LA-ICP-MS zircon geochronology for Late Cretaceous felsic dikes and intermediate volcanic rocks hosted in Mersin ophiolite, South Turkey and its implications

Nusret Nurlu 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.2

LA-ICP-MS U-Pb geochronology of zircons, whole-rock (main, trace, and REE) geochemistry, and mineral chemistry (feldspars) are constrained for felsic dikes and intermediate volcanic rocks of the Mersin ophiolite in the Inner Tauride Suture Zone (Southern Turkey). The geochronological research, dependent on LA-ICP-MS U-Pb zircon analyses from examined rocks, has yielded a concordia age of 87.38 ± 0.32 Ma for a microgranular felsic dike, stating a Coniacian (Late Cretaceous) age. The felsic dikes show mainly hemicrystalline, aphanitic, porphyritic textures and petrographic analyses from the felsic dikes, and volcanic rocks exhibit that they are mainly dacite, rhyodacite, andesite and basaltic andesite, which are poor in mafic minerals. The mineral chemistry of the dacite and rhyodacite dikes present that plagioclases have a wide range of contents, from andesine (An31.1–49.7) to albite (An0.3–28.15) and K-feldspars represented by sanidine (Or42.5–93.3). Dacite/aplite dikes cutting mainly andesitic volcanic rocks present island arc tholeiite-like geochemistry. These felsic intrusive rocks are depleted in HFSE (high-field-strength elements), enriched in LILE (large-ion lithophile elements) and present flat-type REE trends; these patterns furthermore verify their supra-subduction zone geodynamic setting. The initial phase of arc-type volcanics formed above, as can be observed in most of the ophiolites in the Inner Tauride Suture Zone. The arctype volcanics and SSZ-type slab (of metamorphic rock and ophiolite) are cut by dacitic rocks (Coniacian). From the geochronology, field relations, and geochemical evidence from the felsic dikes and volcanics, it can be concluded that the Mersin ophiolite occurred in a tectonic environment (subduction zone) in the southern branch of the Neo-Tethys, located in modern Southern Anatolia.

Computation of Stabilizing PI-PD Controllers

Nusret Tan 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.2

The PI-PD controller structure provides an excellent four-parameter controller for control of integrating, unstable and resonant processes to set point changes while the conventional PID controller has limitations in controlling such systems. In this paper, a graphical method for the computation of all stabilizing PI-PD controllers is given. The proposed method is based on plotting the stability boundary locus, which is a locus dependent on the parameters of the controller and frequency, in the parameter plane. The stability boundary loci are first obtained in the and planes and then it is shown that all the stabilizing values of the parameters of a PI-PD controller can be found. Compu-tation of stabilizing PI-PD controllers which achieve user specified gain and phase margins is also studied. The method is used to design robust PI-PD controllers for control systems with parametric un-certainties. A design procedure for interval control systems is proposed. Examples are given to show the benefit of the method presented.

Design of Robust PI Controller for Vehicle Suspension System

Celaleddin Yeroglu,Nusret Tan 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.1

This paper deals with the design of a robust PI controller for a vehicle suspension system. A method, which is related to computation of all stabilizing PI controllers, is applied to the vehicle suspension system in order to obtain optimum control between passenger comfort and driving performance. The PI controller parameters are calculated by plotting the stability boundary locus in the (kp , ki)-plane and illustrative results are presented. In reality, like all physical systems, the vehicle suspension system parameters contain uncertainty. Thus, the proposed method is also used to compute all the parameters of a PI controller that stabilize a vehicle suspension system with uncertain parameters.

Design of Robust PI Controller for Vehicle Suspension System

Yeroglu, Celaleddin,Tan, Nusret The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.1

This paper deals with the design of a robust PI controller for a vehicle suspension system. A method, which is related to computation of all stabilizing PI controllers, is applied to the vehicle suspension system in order to obtain optimum control between passenger comfort and driving performance. The PI controller parameters are calculated by plotting the stability boundary locus in the $(k_p,\;k_i)$-plane and illustrative results are presented. In reality, like all physical systems, the vehicle suspension system parameters contain uncertainty. Thus, the proposed method is also used to compute all the parameters of a PI controller that stabilize a vehicle suspension system with uncertain parameters.

Oxytocin Levels in Children with Separation Anxiety and Their Mothers before and after Treatment

Nur Seda Gülcü Üstün,Şefika Nur Gümüş,Nusret Soylu 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.3

Objective: The purpose of this study was to compare the plasma oxytocin levels of children with separation anxiety disorder (SAD) and their mothers with those of healthy controls and to examine the relationship between oxytocin levels and changes in anxiety three months after treatment. Methods: Thirty children aged 6−12 years with SAD, 30 healthy children, and mothers of both groups were included in the study. All cases were evaluated with semi-structured interview and Clinical Global Impression Scale. All cases and mothers of both groups filled out scales to determine various psychological variables (anxiety, depression, and attachment). The patient group children were re-evaluated with their mothers after three months, following treatment. Plasma oxytocin levels were evaluated from both groups and their mothers before and after treatment. Results: The plasma oxytocin levels of mothers of children with SAD were significantly lower than those of the controls and increased significantly three months after their children were treated. No difference was found between the plasma oxytocin levels of children with SAD and the control group, and these children’s levels decreased significantly after treatment. A positive correlation was found between changes in the plasma oxytocin levels of children with SAD and the change in anxiety scores. Conclusion: Our results show that the change in plasma oxytocin levels in both children and mothers after treatment suggests that oxytocin may be important in the etiology of SAD.

Protective Role of Selenium and High Dose Vitamin E against Cisplatin - Induced Nephrotoxicty in Rats

Aksoy, Asude,Karaoglu, Aziz,Akpolat, Nusret,Naziroglu, Mustafa,Ozturk, Turkan,Karagoz, Zuhal Karaca Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

Background: Cisplatin (CDDP) is one of the most active cytotoxic agents in the treatment of cancer. We investigated the effect of selenium (Se) with high dose vitamin E (VE) administration to prevent CDDP-induced nephrotoxicity in rats. Materials and Methods: In this study, 40 female Wistar rats were randomly divided into five equal groups. The first group, which served as the control, was administered physiological saline (2.5 cc/day, 5 days) intraperitoneally (IP), while group A was administered cisplatin (6 mg/kg BW/ single dose) plus physiological saline IP. Groups B, C, D received IP five doses of Se (1.5 mg/kg BW), and a high dose of VE (1000 mg/kg BW) (Se-VE) in combination before, simultaneously, and after CDDP, respectively. The rats were sacrificed five days after CDDP administration. Plasma malondialdehide (MDA), glutathione peroxidase (GSH-Px), reduced glutathione (GSH), catalase, urea, creatinine levels, renal histopathological changes were measured. Results: The histopathological injury score, plasma levels of MDA, urea, creatinine were found to increase in group A compared to the control (p<0.05), while plasma levels of GSH-Px, GSH and catalase decreased (p<0.05). In contrast, plasma levels of MDA decreased (p<0.05) in groups B, C, D, which were treated with Se- VE, whereas levels of GSH-Px, GSH were found to increase only for group D (p<0.05). Plasma urea, creatinine levels improved in the treatment groups compared to group A (p<0.001). Histopathological changes caused by CDDP were also significantly improved after Se-VE treatment (p<0.05). Conclusions: Oxidative stress increases with CDDP-induced nephrotoxicity in rats. Se-VE supplementation might thus play a role in the prevention of CDDP-induced nephrotoxicity in patients.

Characteristics of patients operated for primary hyperparathyroidism at university hospitals in Türkiye

Turkay Kirdak,Nuh Zafer Canturk,Nusret Korun,Gokhan Ocakoglu 대한외과학회 2016 Annals of Surgical Treatment and Research(ASRT) Vol.91 No.1

Purpose: The aim of this study was to define the clinical and laboratory characteristics of patients operated on for primary hyperpatathyroidism (PHPT) at university hospitals in Türkiye, and to investigate the differences in the clinical presentations of the disease between different geographical regions. Methods: Patients operated on for PHPT in the university hospitals of Türkiye were included in the study. The demographic, clinical, and laboratory findings and the operational data of the patients were investigated according to the whole country and to different geographical regions. Comparisons were performed according to whole country and regions. Results: A total of 1,162 cases were included in the study from different regions and 20 university hospitals. The mean age of patients was 52.4 ± 0.38 (mean ± standard error) in the general population of Türkiye. The rates of hypertension, urolithiasis, bone disease and 25-hydroxyvitamin D insufficiency were 35%, 18.6%, 67.6%, and 63%, respectively. The median parathormone (PTH), serum total calcium (Ca<SUP>+2</SUP>) and phosphorus value were 220 pg/mL (range, 70–2,500 pg/mL), 11.2 mg/dL (range, 9.5–11.2 mg/dL), and 2.4 mg/dL (range, 1–4.7 mg/dL), respectively. The median size of the adenomas resected was 16 mm (range, 4–70 mm). Significant differences were observed in the clinical and laboratory findings of the patients operated on due to PHPT between different geographical regions of Türkiye (P < 0.05). Conclusion: The clinical and laboratory characteristics of the patients with PHPT in different geographical regions of Türkiye differ. Furthermore, the general findings of the cases in Türkiye give us a hint that the severity of the disease here is somewhere between Eastern and Western countries.

Frequency Response Computation of Fractional Order Interval Transfer Functions

Celaleddin Yeroğlu,M. Mine Ozyetkin,Nusret Tan 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.5

The paper present extensions of some results developed in the parametric robust control to fractional order interval control systems (FOICS). Computation of the Bode and Nyquist envelopes of FOICS are studied. Using the geometric structure of the value set of fractional order interval polynomials (FOIP), a technique is proposed for computing the Bode and Nyquist envelopes of transfer functions whose numerator and denominator polynomials are fractional order polynomials with interval uncertainty structure. The results obtained are useful for the analysis and design of FOICS. Numerical examples are included to illustrate the benefit of the method presented.

Lumbar Disc Herniation in a Patient With Congenital Vertebral Body Anomaly: A Case Report

Cem Atabey,Ahmet Eroğlu,Ali Kivanc Topuz,Murat Velioğlu,Mehmet Nusret Demircan 대한척추신경외과학회 2014 Neurospine Vol.11 No.4

Lumbar disc herniation is characterized with low back and leg pain resulting from the degenerated lumbar disc compressing the spinal nerve root. The etiology of degenerative spine is related to age, smoking, microtrauma, obesity, disorders of familial collagen structure, occupational and sports-related physical activity. However, disc herniations induced by congenital lumbar vertebral anomalies are rarely seen. Vertebral fusion defect is one of the causes of congenital anomalies. The pathogenesis of embryological corpus vertebral fusion anomaly is not fully known. In this paper, a 30- year-old patient who had the complaints of low back and right leg pain after falling from a height is presented. She had right L5-S1 disc herniation that had developed on the basis of S1 vertebra corpus fusion anomaly in Lumbar computed tomography. This case has been discussed in the light of literature based on evaluations of Lumbar Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This case is unique in that it is the first case with development of lumbar disc herniation associated with S1 vertebral corpus fusion anomaly. Congenital malformations with unusual clinical presentation after trauma shouldbe evaluated through advanced radiological imaging techniques.