LATERAL STABILITY CONTROL OF FULLY ELECTRIC VEHICLES

M. T. EM RLER,K. KAHRAMAN,M. ENTÜRK,O. U. ACAR,B. AKSUN GÜVENÇ,L. GÜVENÇ,B. EFEND O LU 한국자동차공학회 2015 International journal of automotive technology Vol.16 No.2

The problem of vehicle lateral stability control for fully electric vehicles is addressed in this paper using two different approaches. One of them is a novel integrated lateral stability control (ILSC) system and the second one is a regenerative braking based lateral stability control system (RB-LSC). The proposed ILSC system is based on corrective yaw moment calculation, braking torque distribution and electric motor torque reduction. The proposed second method – RB-LSC - is a simpler method than the ILSC system. In this method, electric motor torque is regulated according to the vehicle side slip error and/or the vehicle yaw rate error. The performances of the proposed methods are evaluated under severe road conditions and extreme maneuvers using the commercially available CarSim vehicle dynamics software. The results show that the proposed control systems improve vehicle lateral stability significantly.

Highly efficient removal from aqueous solution by adsorption of Maxilon Red GRL dye using activated pine sawdust

İlknur Şentürk,Muhammed Reha Yıldız 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.6

Pine sawdust, to which sulfuric acid was applied (APSD), was utilized as an inexpensive adsorbent to perform the batch adsorptive removal from a synthetic dye solution of Maxilon Red GRL (MR GRL). The activated adsorbent was characterized by the points of zero charge, FTIR, N2 adsorption-desorption, SEM, and SEM-EDX analyses. According to the removal results, the highest efficiency of the dye adsorption was reached at 180min. MR GRL removal of 99.35% was achieved using APSD under the optimum conditions (pH=5.7-6.0, temperature=298 K, dye concentration= 250mg/L, and adsorbent dosage=8 g/L). The Langmuir isotherm represents the best explanation model for the experimental data, which has the highest adsorption capacity of 312.5mg/g at 318 K. The compatibility of adsorption with the Langmuir isotherm showed that adsorption was reversible and physical. The other results obtained confirmed this situation. The kinetic research demonstrated that the sorption process was realized in accordance with the pseudo-second- order kinetic model. The thermodynamic parameters revealed that the MR GRL adsorption occurred spontaneously and was exothermic. The findings of the present research confirm that acid-activated pine sawdust may be utilized to remove MR GRL dye from aqueous solutions as a low-cost and efficient adsorbent.

Endoscopic ultrasound-guided gastrojejunostomy with a direct technique without previous intestinal filling using a tubular fully covered self-expandable metallic stent

Hakan Şentürk,İbrahim Hakkı Köker,Koray Koçhan,Sercan Kiremitçi,Gülseren Seven,Ali Tüzün İnce 대한소화기내시경학회 2024 Clinical Endoscopy Vol.57 No.2

Background/Aims: Endoscopic ultrasonography-guided gastrojejunostomy is a minimally invasive method for the management of gastric outlet obstruction. Conventionally, a lumen-apposing metal stent (LAMS) is used to create an anastomosis. However, LAMS is expensive and not widely available. In this report, we described a tubular fully covered self-expandable metallic stent (T-FCSEMS) for this purpose. Methods: Twenty-one patients (15 men [71.4%]; median age, 66 years; range, 40–87 years) were included in this study. A total of 19 malignant (12 pancreatic, 6 gastric, and 1 metastatic rectal cancer) and 2 benign cases were observed. The proximal jejunum was punctured with a 19 G needle. The stomach and jejunum walls were dilated with a 6 F cystotome, and a 20×80 mm polytetrafluoroethylene T-FCSEMS (Hilzo) was deployed. Oral feeding was initiated after 12 to 18 hours and solid foods after 48 hours. Results: The median procedure time was 33 minutes (range, 23–55 minutes). After two weeks, 19 patients tolerated oral feeding. In patients with malignancy, the median survival time was 118 days (range, 41–194 days). No serious complications or deaths occurred. All patients with malignancy tolerated oral food intake until they expired. Conclusions: T-FCSEMS is safe and effective. This stent should be considered as an alternative to LAMS for gastric outlet obstruction.

High-impact chronic pain: evaluation of risk factors and predictors

İlteriş Ahmet Şentürk,Erman Şentürk,Işıl Üstün,Akın Gökçedağ,Nilgün Pulur Yıldırım,Nilüfer Kale İçen 대한통증학회 2023 The Korean Journal of Pain Vol.36 No.1

Background: The concept of high-impact chronic pain (HICP) has been proposed for patients with chronic pain who have significant limitations in work, social life, and personal care. Recognition of HICP and being able to distinguish patients with HICP from other chronic pain patients who do not have life interference allows the necessary measures to be taken in order to restore the physical and emotional functioning of the affected persons. The aim was to reveal the risk factors and predictors associated with HICP. Methods: Patients with chronic pain without life interference (grade 1 and 2) and patients with HICP were compared. Significant data were evaluated with regression analysis to reveal the associated risk factors. Receiving operating characteristic (ROC) analysis was used to evaluate predictors and present cutoff scores. Results: One thousand and six patients completed the study. From pain related cognitive processes, fear of pain (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.87–0.98; P = 0.007) and helplessness (OR, 1.06; 95% CI, 1.01–1.12; P = 0.018) were found to be risk factors associated with HICP. Predictors of HICP were evaluated by ROC analysis. The highest discrimination value was found for pain intensity (cut-off score > 6.5; 83.8% sensitive; 68.7% specific; area under the curve = 0.823; P < 0.001). Conclusions: This is the first study in our geography to evaluate HICP with measurement tools that evaluate all dimensions of pain. Moreover, it is the first study in the literature to evaluate predictors and cut-off scores using ROC analysis for HICP.

Kyphosis After Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

Onur Yaman,Mehmet Zileli,Salim Şentürk,Kemal Paksoy,Salman Sharif 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Thoracolumbar fractures change the biomechanics of the spine. Load distribution causes kyphosis by the time. Treatment of posttraumatic kyphosis is still controversial. We reviewed the literature between 2010 and 2020 using a search with keywords “thoracolumbar fracture and kyphosis.” We removed osteoporotic fractures, ankylosing spondylitis fractures, non-English language papers, case reports, and low-quality case series. Up-to-date information on posttraumatic kyphosis management was reviewed to reach an agreement in a consensus meeting of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. The first meeting was conducted in Peshawar in December 2019 with WFNS Spine Committee members’ presence and participation. The second meeting was a virtual meeting via the internet on June 12, 2020. We utilized the Delphi method to administer the questionnaire to preserve a high degree of validity. We summarized 42 papers on posttraumatic kyphosis. Surgical treatment of thoracolumbar kyphosis due to unstable burst fractures can be done via a posterior only approach. Less blood loss and reduced surgery time are the main advantages of posterior surgery. Kyphosis angle for surgical decision and fusion levels are controversial. However, global sagittal balance should be taken into consideration for the segment that has to be included. Adding an intermediate screw at the fractured level strengthens the construct.

Source parameters for small–moderate earthquakes in Marmara Region (Turkey)

Tahir Serkan Irmak,Evrim Yavuz,Hamdullah Livaoğlu,Erman Şentürk,Emre Y. Sahin 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.5

The main aim of this study is to investigate the self-relation and self-similarity of earthquakes in and around the Marmara Sea (NW Turkey) by using these obtained source parameters. With this purpose, spectral source parameters for 77 small to moderate earthquake (3.5 ≤ ML ≤ 5.2) that occurred during 2004–2018 have been determined from P and S wave spectra according to Brune’s source model by using regional broadband seismograms. The average ratio of P/S wave corner frequency is found to be 1.3 that suggesting higher corner frequency for P wave. The static stress drops range from 0.1 and 136 MPa with a median value of 9.8 MPa (98 bars). The high stress drops for these events can indicate high frictional strength and low strain-rate of the faults. Similarly, the low values of the stress drop can indicate a general weakness of the faults in the study area. There is no clear dependence between the seismic moment and the static stress drop in the analyzed events but some events which have lower seismic moment value also have lower stress drop. Obtaining results indicated the corner frequency decreases with increasing of the seismic moment. Also, a slight depth dependence of the corner frequency has been observed for the analyzed events. Shallower events have larger corner frequency value than deeper events. Also, a clear depth dependence of the stress drop values has not been observed. However, the depth dependence of the seismic moment is seen more clearly. Our results indicated that the deeper events have larger seismic moment values in the study area. In spite of scattering in small events, a linear relationship between local magnitude (ML) and moment magnitude (MW) could be obtained as MW = 1.4261(± 0.31) + 0.6399(± 0.08)ML from P waves spectra and MW = 0.0136(± 0.21) + 0.9883(± 0.05)ML from S wave spectra and calculated MW values are consistent with waveform inversion (centroid moment tensor – CMT) results. These relationships may be useful for seismic hazard studies in the study area.

Concordance of Endoscopic Ultrasonography-Guided Fine Needle Aspiration Diagnosis with the Final Diagnosis in Subepithelial Lesions

Erkan Çağlar,İbrahim Hatemi,Deniz Atasoy,Gürhan Şişman,Hakan Şentürk 대한소화기내시경학회 2013 Clinical Endoscopy Vol.46 No.4

Background/Aims: In this study we aimed to determine the rate of concordance of endoscopic ultrasonography (EUS)-guided fine needle aspiration (FNA) diagnosis with the final diagnosis obtained by surgery or endoscopic resection and follow-up in upper gastrointestinal subepithelial lesions. Methods: We retrospectively studied patients with subepithelial lesions who underwent EUS at our center from 2007 to 2011. Results: We had a final diagnosis in 67 patients (mean age±SD, 51.23±12.48 years, 34.3% [23] female, 65.6% [44] male). EUS-FNA was performed in all of the patients. On-site pathology was not performed. In nine of the patients, the obtained material which was obtained was insufficient. The cytologic examination was benign in 31 and malignant in 27 of the patients. Based on the final diagnosis, the EUS-FNA had a sensitivity of 96%, a specificity of 100%, and a diagnostic yield of 85%. Conclusions: The diagnostic yield of EUS-FNA, in the absence of the on-site cytopathologist, is feasible for the diagnosis of subepithelial lesions of the upper gastrointestinal system.

Cyst Fluid Carcinoembryonic Antigen Level Difference between Mucinous Cystic Neoplasms and Intraductal Papillary Mucinous Neoplasms

Ibrahim Hakkı Köker,Nurcan Ünver,Fatma Ümit Malya,Ömer Uysal,Elmas Biberci Keskin,Hakan Şentürk 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.1

Background/Aims: The role of cyst fluid carcinoembryonic antigen (CEA) level in differentiating mucinous pancreatic cystic lesions(PCLs) is controversial. We investigated the role of cyst fluid CEA in differentiating low-risk (LR)-intraductal papillary mucinousneoplasms (IPMNs) from high-risk (HR)-IPMNs and LR-mucinous cystic neoplasms (MCNs). Methods: This was a retrospective study of 466 patients with PCLs who underwent endoscopic ultrasound-guided fine-needleaspirationover a 7-year period. On histology, low-grade dysplasia and intermediate-grade dysplasia were considered LR, whereashigh-grade dysplasia and invasive carcinoma were considered HR. Results: Data on cyst fluid CEA levels were available for 50/102 mucinous PCLs with definitive diagnoses. The median CEA (range)levels were significantly higher in HR cysts than in LR cysts (2,624 [0.5–266,510] ng/mL vs. 100 [16.8–53,445] ng/mL, p=0.0012). The area under the receiver operating characteristic curve (AUROC) was 0.930 (95% confidence interval [CI], 0.5–0.8; p<0.001) fordifferentiating LR-IPMNs from LR-MCNs. The AUROC was 0.921 (95% CI, 0.823–1.000; p<0.001) for differentiating LR-IPMNsfrom HR-IPMNs. Both had a CEA cutoff level of >100 ng/mL, with a negative predictive value (NPV) of 100%. Conclusions: Cyst fluid CEA levels significantly vary between LR-IPMNs, LR-MCNs, and HR-IPMNs. A CEA cutoff level of>100 ng/mL had a 100% NPV in differentiating LR-IPMNs from LR-MCNs and HR-IPMNs.