Special cases in fatigue analysis of wind turbines

Onur Güneş,Elif Altunsu,Ali Sari 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.5

The turbine industry demands a reliable design with affordable cost. As technological advances begin to support turbines of huge sizes, and the increasing importance of wind turbines from day to day make design safety conditions more important. Wind turbines are exposed to environmental conditions that can affect their installation, durability, and operation. International Electrotechnical Commission (IEC) 61400-1 design load cases consist of analyses involving wind turbine operating conditions. This design load cases (DLC) is important for determining fatigue loads (i.e., forces and moments) that occur as a result of expected conditions throughout the life of the machine. With the help of FAST (Fatigue, Aerodynamics, Structures, and Turbulence), an open source software, the NREL 5MW land base wind turbine model was used. IEC 61400-1 wind turbine design standard procedures assessed turbine behavior and fatigue damage to the tower base of dynamic loads in different design conditions. Real characteristic wind speed distribution and multi-directional effect specific to the site were taken into consideration. The effect of these conditions on the economic service life of the turbine has been studied.

Evaluation of Paraoxonase, Arylesterase and Malondialdehyde Levels in Schizophrenia Patients Taking Typical, Atypical and Combined Antipsychotic Treatment

Mehmet Güneş,Mehmet Akif Camkurt,Mahmut Bulut,Süleyman Demir,Aslıhan Okan İbiloğlu,Mehmet Cemal Kaya,Abdullah Atlı,İbrahim Kaplan,Aytekin Sir 대한정신약물학회 2016 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.14 No.4

Objective: Human serum paraoxonase (PON1) prevents lipids from peroxidation and functions as an antioxidant mechanism. Malonyldialdehyde (MDA) is the final product of lipid peroxidation and can be used as an indicator of oxidative stress. The aim of this study was to investigate PON1, MDA, and arylesterase (ARY) levels in schizophrenic patients who are taking typical, atypical, or combined (typical and atypical) antipsychotic drug treatment, with respect to those of healthy controls. Methods: We evaluated 41 patients (11 taking typical antipsychotics, 19 taking atypical antipsychotics, 11 taking combined antipsychotics) and 43 healthy controls. Results: MDA levels were higher in schizophrenic patients taking typical antipsychotics compared with healthy controls (p=0.001). ARY levels were higher in patients taking atypical antipsychotics compared with healthy controls (p=0.005). PON1 activity was similar in all groups. Conclusion: Our results indicate that treatment with typical antipsychotic drugs could be related to increased MDA levels; and antipsychotic medication may increase PON1 levels in schizophrenic patients.

The authors reply: Predictive role of hematologic parameters in testicular torsion

Mustafa Güneş,Mehmet Umul,Muammer Altok 대한비뇨의학회 2015 Investigative and Clinical Urology Vol.56 No.8

Predictive role of hematologic parameters in testicular torsion

Mustafa Güneş,Mehmet Umul,Muammer Altok,Mehmet Akyuz,Cemal Selcuk İşoğlu,Fatih Uruc,Bekir Aras,Alpaslan Akbaş,Ercan Baş 대한비뇨의학회 2015 Investigative and Clinical Urology Vol.56 No.4

Purpose: To evaluate the predictive role of the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV), and platelet count (PLT) in the diagnosis of testicular torsion (TT) and testicular viability following TT. Materials and Methods: We analyzed two study groups in this retrospective study: 75 patients with a diagnosis of TT (group 1) and 56 age-matched healthy subjects (group 2). We performed a complete blood count as a part of the diagnostic procedure, and NLR, PLR, MPV, and PLT values were recorded. We compared the patient and control groups in terms of these parameters. Then, TT patients were divided into two subgroups according to the time elapsed since the onset of symptoms. Subsequently, we evaluated the relationship between the duration of symptoms and these parameters. Results: There were significant differences between groups 1 and 2 in NLR, PLR, and PLT (p<0.001 for all). There was no predictive role of MPV in the diagnosis of TT (p=0.328). We determined significantly high sensitivity and specificity levels for NLR in the prediction of TT diagnosis (84% and 92%, respectively). Furthermore, NLR was significantly related to the duration of symptoms in TT patients (p=0.01). Conclusions: NLR may be a useful parameter in the diagnosis of TT. Furthermore, NLR may be used as a predictive factor for testicular viability following TT.

Risperidone Induced Pisa Syndrome in a Male Adolescent

Serkan Güneş,Özalp Ekinci,Meltem Çobanoğulları Direk,Veli Yıldırım,Çetin Okuyaz,Fevziye Toros 대한정신약물학회 2016 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.14 No.1

Pisa syndrome, a rare dystonic reaction resulting from prolonged exposure to antipsychotic medications, is characterized by persistent dystonia of trunk muscles and abnormal posture. It is called Pisa syndrome, because the abnormal posture resembles the Leaning Tower of Pisa. Different from other types of dystonic reactions, Pisa syndrome is more prevalent in females and in older patients with organic brain changes. A 15-year-old male patient with mental retardation was admitted to pediatric neurology clinic for the complaint of abnormal posturing. He had been taking only risperidone for the last four years. Over the last month, the patient gradually developed tonic flexion of trunk and head toward left and was diagnosed with Pisa syndrome. In this paper, we aimed to discuss the association between risperidone use and Pisa syndrome in light of the available literature.

Risperidone Related Raynaud’s Phenomenon: An Adolescent Case

Serkan Güneş,Özalp Ekinci,Halenur Teke,Veli Yıldırım 대한정신약물학회 2018 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.16 No.1

Raynaud’s phenomenon is a recurrent vasospastic condition with reducing in peripheral blood flow due to cold, or emotional stress. White, blue and red discolorations occur during the attacks. Serotonin reuptake inhibitors, psychostimulants, and aripiprazole are reported to be related with Raynaud’s phenomenon. Risperidone is an atypical antipsychotic drug with dopaminergic and serotonergic effects. In children and adolescents, risperidone is used for bipolar disorder, tic disorders, conduct disorder, schizophrenia, symptoms of irritability and self-mutilation. Here we report a case of Raynaud’s phenomenon associated with risperidone in a 12-year-old boy. Raynaud’s phenomenon occurred two weeks after starting risperidone and disappeared after stopping risperidone.

The association between pain, balance, fall, and disability in patients with lumbar spinal stenosis with vascular claudication

( Musa Güneş ),( Tarık Özmen ),( Tuğba Moralı Güler ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.4

Background: The effect of lumbar spinal stenosis (LSS) and peripheral vascular disease (PVD), which occurs with similar degenerative conditions, when seen together, has not been studied. The aim of this study is to examine and compare the relationship between pain, balance, disability, fear of falling, and kinesiophobia in LSS patients with intermittent vascular claudication (IVC). Methods: Seventy-two patients diagnosed with LSS using magnetic resonance imaging participated in this study. Thirty-five patients with IVC symptoms and showing vascular lesions by lower extremity venous and arterial Doppler ultrasonography imaging were included in the IVC-LSS group. The pain, static balance, dynamic balance, disability, fear of falling, and kinesiophobia were evaluated using the numeric rating scale, single leg stance test, Time Up and Go (TUG), the Oswestry Disability Index (ODI), Fall Efficacy Scale-International (FES-I), and Tampa Scale for Kinesiophobia (TSK), respectively. Results: Age and female sex were found to be higher in the IVC-LSS group (P = 0.024; P = 0.012). The IVC-LSS group had a shorter single leg stance time and TUG test duration, pain intensity, ODI, FES-I, and TSK scores were higher than patients with LSS (P = 0.001). Pain, fear of falling, and kinesiophobia were moderately correlated with disability in the IVC-LSS group. No relationship was found between pain and dynamic balance. Also, the pain was not related to kinesiophobia. Conclusions: The findings indicated that IVC causes loss of balance and an increase in pain, disability, fear of falling, and kinesophobia in patients with LSS.

UV-LIGHT-ASSISTED OXIDATIVE sp^3 HYBRIDIZATION OF GRAPHENE

FETHULLAH GÜNEŞ,한강희,신현진,이시영,MEIHUA JIN,DINH LOC DUONG,채승진,김은성,FEI YAO,ANASS BENAYAD,최재영,이영희 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.5

We report the transformation of electronic structures of sp^2 graphene to sp^3 graphene by UV-light-assisted oxidation. Two distinctive oxidation mechanisms were observed during this metal–insulator transition: (i) At low-oxidation regime, p-doping behavior by oxygen species extracting electrons from graphene and (ii) at high-oxidation regime, n-doping behavior by electron-hopping via strongly localized oxide states. We also found that the dominant oxygen-related functional group by UV-light-assisted oxidation was an epoxide group rather than hydroxyl group, which differed from conventional graphite oxide.

An Analysis of Myocardial Efficiency in Patients with Severe Asymptomatic Mitral Regurgitation

Rengin Çetin Güvenç,Emre Aruğaslan,Tolga Sinan Güvenç,Fatma Özpamuk Karadeniz,Hülya Kaşıkçıoğlu,Neşe Çam 한국심초음파학회 2020 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.28 No.4

BACKGROUND: It is difficult to determine left ventricular systolic performance in patients with severe mitral regurgitation (MR) since left ventricular ejection fraction (EF) could be preserved until the end stages of the disease. Myocardial efficiency (MEf) describes the amount of external work (EW) done by the left ventricle per unit of oxygen consumed (mVO2). In the present study, we aimed to investigate MEf in patients with asymptomatic severe MR using a novel echocardiographic method. METHODS: A total of 27 patients with severe asymptomatic MR and 26 healthy volunteers were included in this cross-sectional study. EW was measured using stroke volume and blood pressure, while mVO2 was estimated using double product and left ventricular mass. RESULTS: There were no differences between the groups with regards to EF (66% ± 5% vs. 69% ± 7%), while MEf was significantly reduced in patients with severe MR (25% ± 11% vs. 44% ± 12%, p < 0.001). This difference was maintained even after adjustment for age, gender and body surface area (adjusted ̅ : 0.44, 95% CI: 0.39–0.49 for controls and adjusted ̅ : 0.24, 95% CI: 0.19–0.29 for patients with severe MR). Further analysis showed that this reduction was due to an increase in total mVO2 in the severe MR group. MEf of thepatients who were both on β-blockers and angiotensin converting enzyme inhibitors/angiotensin receptor blockers were higher than those who were not on any drugs, but this difference was not statistically significant (32% ± 15% vs. 23% ± 9%, p = 0.41). CONCLUSIONS: MEf was significantly lower in patients with asymptomatic severe MR and preserved EF.

Influence of access cavity design on calcium hydroxide removal using different cleaning protocols: a confocal laser scanning microscopy study

Falakaloğlu Seda,Yeniçeri Özata Merve,Güneş Betül,Silva Emmanuel João Nogueira Leal,Gündoğar Mustafa,Güçyetmez Topal Burcu 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.3

Objectives The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC.Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex. Objectives The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC.Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.