Adult Proximal Humeral Locking Plate Is a Good Alternative Option in the Treatment of Adolescent Subtrochanteric Femur Fractures: A Case Series and Literature Review

( Ceyhun Çag˘lar ),( Serhat Akçaalan ),( Merve Bozer ),( Mustafa Akkaya ) 대한고관절학회 2022 Hip and Pelvis Vol.34 No.4

Purpose: Management of pediatric subtrochanteric femur fractures (SFFs) is difficult. The aim of this study was to evaluate the outcomes of adolescent SFFs treated with adult proximal humeral locking plates (PHLPs). Materials and Methods: A retrospective analysis of 18 adolescents (11 male, 7 female) with a diagnosis of SFF who underwent internal fixation with a PHLP was conducted. Data regarding injury mechanism, fracture pattern, and time to union were recorded for all patients. In addition, a clinical and functional evaluation of patients was performed using the Harris hip score (HHS), Iowa hip score (IHS), modified Merle d’Aubigne-Postel score (MMAPS), Flynn criteria, and hip range of motion (ROM). Results: The mean age of the patients was 12.72±2.05 years (range, 10-16 years). Radiological observation was performed for evaluation of five different injury mechanisms and different fracture patterns in patients. The mean postoperative HHS was 92.27±5.61, the mean IHS was 90.88±6.46, and the mean MMAPS was 17.22±0.94. According to the Flynn criteria, excellent results were achieved in 14 cases and satisfactory results were obtained in four cases. Measurements of the patients’ mean hip ROM values were as follows: 17.77±3.52。in extension, 115.27±6.74。in flexion, 43.05±3.48。in abduction, 27.50±4.28。in adduction, 42.22±4.60。in internal rotation, and 42.22±3.91。in external rotation. Conclusion: Surgery performed on adolescent patients using an adult PHLP showed good, safe results. Therefore, it should be considered as an alternative option.

Shear strengthening of reinforced concrete beams with minimum CFRP and GFRP strips using different wrapping technics without anchoring application

Ceyhun Aksoylu 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.6

In this study, the performance of shear deficient reinforced concrete (RC) beams with rectangular cross-sections, which were externally bonded reinforced (EBR) with high strength CFRP and GFRP strips composite along shear spans, has been experimentally and analytically investigated under vertical load. In the study, the minimum CFRP and GFRP strips width over spacing were considered. The shear beam with turned end to a bending beam was investigated by applying different composite strips. Therefore various arising in each of strength, ductility, rigidity, and energy dissipation capacity were obtained. A total of 12 small-scaled experimental programs have been performed. Beam dimensions have been taken as 100x150x1000 mm. Four beams have been tested as unstrengthened samples. This paper focuses on the effect of minimum CFRP and GFRP strip width on behaviours of RC beams shear-strengthened with full-wrapping, U-wrapping, and U-wrapping+longitudinal bonding strips. Strengthened beams showed significant increments for flexural ductility, energy dissipation, and inelastic performance. The full wrapping strips applied against shear failure have increased the load-carrying capacity of samples 53%- 63% interval rate. Although full wrapping is the best strengthening choice, the U-wrapping and U-wrapping+longitudinal strips of both CFRP and GFRP bonding increased the shear capacity by 53%~75% compared to the S2 sample. In terms of ductility, the best result has been obtained by the type of strengthening where the S5 beam was completely GFRP wrapped. The experimental results were also compared with the analytically given by ACI440.2R-17, TBEC-2019 and FIB-2001. Especially in U-wrapped beams, the estimation of FIB was determined to be 81%. The estimates of the other codes are far from meeting the experimental results; therefore, essential improvements should be applied to the codes, especially regarding CFRP and GFRP deformation and approaches for longitudinal strip connections. According to the test results, it is suggested that GFRP, which is at least as effective but cheaper than CFRP, may be preferred for strengthening applications.

Numerical and analytical investigation of parameters influencing the behavior of shear beams strengthened by CFRP wrapping

Ceyhun Aksoylu,Yasin Onuralp Özkılıç,Şakir Yazman,Mohammed Alsdudi,Lokman Gemi,Musa Hakan Arslan 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

In this study, a parametric study was performed considering material properties of concrete, material properties of steel, the number of longitudinal reinforcement (reinforcement ratio), CFRP ply orientations, a number of layers as variables by using ABAQUS. Firstly, the parameters used in the Hashin failure criteria were verified using four coupon tests of CFRP. Secondly, the numerical models of the beams strengthened by CFRP were verified using five experimental data. Finally, eighty numerical models and eighty analytic calculations were developed to investigate the effects of the aforementioned variables. The results revealed that in the case of using fibrous polymer to prevent shear failure, the variables related to reinforced concrete significantly affected the behavior of specimens, whereas the variables related to CFRP composite have a slight effect on the behavior of the specimens. As a result of numerical analysis, while the increase in the longitudinal tensile and compression reinforcement, load bearing capacity increases between 23.6%-70.7% and 5.6%-12.2%, respectively. Increase in compressive strength (29 MPa to 35 MPa) leads to a slight increase in the load-carrying capacity of the specimens between 4.6% and 7.2%. However, the decrease in the compressive strength (29 MPa to 20 MPa) significantly affected (between 6.4% and 8.1% decrease observed) the behavior of the specimens. As the yield strength increases or decreases, the capacity of specimens increase approximately 27.1% or decrease 12.1%. The effects of CFRP ply orientation results have been obtained as a negligible well approximately 3.7% difference. An increasing number of CFRP layers leads to almost no effect (approximately 2.8%) on the behavior of the specimen. Finally, according to the numerical analysis, the ductility values obtained between 4.0 and 6.9 indicate that the beams have sufficient ductility capacity.

Investigation of Precast New Diagonal Concrete Panels in Strengthened the Infilled Reinforced Concrete Frames

Ceyhun Aksoylu,Rifat Sezer 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1

Major part of the structural stock in Turkey doesn’t have sufficient endurance, rigidity and ductility against possible large earthquakes. Strengthening of structures against earthquakes always appears on the agenda and structures are being strengthened by using different techniques. In this context, cast in place reinforced concrete shear walls is a highly effective and reliable method for improving the system behavior. However, construction work takes long time in this method, so the structure is required to be emptied before the practice. For this reason, it is required to develop the strengthening methods which facilitates lives of people and which is economic and effective in terms of structure. The principle of the technique recommended in this study is to convert plastered hollow brick walls of the structure to shear walls equivalent to reinforced concretes (RC) by strengthening them with high-strength precast new diagonal concrete panels. For this purpose, a reinforced concrete frame, which is 1/3 scaled, low-strengthened against earthquake, has two-story and single span unreinforced brick infilling wall, has been produced with failures frequently seen especially in concrete buildings of our country as reference sample. Moreover, strengthening three reinforced concrete infilled frame wall having same features with reference sample by new diagonal concrete panels which are precast, high strengths in different shapes used for the first time in the literature, their behaviors under reversible-repeatable horizontal loading simulating earthquake effect have been tested. Results of the experiment have been compared with the analytic study and it has been observed that applied technique has increased the energy dissipation capacity of test elements and improved the earthquake behaviors.

Experimental analysis of shear deficient reinforced concrete beams strengthened by glass fiber strip composites and mechanical stitches

Ceyhun Aksoylu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.2

This study was conducted to present a new technique to increase the capacity of reinforced concrete beams with insufficient shear reinforcement. Four beam specimens at ½ scale were produced. One of these beams was used for reference, while the other three were strengthened using different methods. The strengthening methods were performed using Mechanical stitches (MS), Glass fiber reinforced polymer (GFRP), and a hybrid of the two (GFRP and MS). In the experiments, the reference beam (E0), the MS-strengthened beam (E1), the GFRP-strengthened beam (E2), and the GFRP+MS-strengthened (E3) beam were tested under vertical load. Following the experiment, vertical load-bearing capacity, ductility value, initial stiffness value, and energy dissipation capacity were calculated for each beam. Afterward, extensive micro and macro damage analyses were performed. In the experiment, the E0 specimen resulted in a failure mode with direct shear damage. The strengthened E1 and E2 beams showed a typical bending behavior. The vertical load-bearing capacity of the E1 and E2 beams increased by 16.8% and 18.1%, respectively, compared to E0. The load-bearing capacity of the newly proposed technique, the hybrid E3 beam, was increased by 19.2%, although it failed with shear damage. Thus, this study has clearly demonstrated that beams with insufficient shear reinforcement can be strengthened using single-layer GFRP (E2). Considering its cost-efficiency compared to other composite materials, it has been suggested that GFRP should be used more widely in the market. In addition, it is reccommended that future studies can use the proposed E1 strengthening for beams weak against shear. The experiments revealed the most appropriate strengthening method for shear beams to be E1>E2>E3 in terms of performance/cost. Finally, the results suggest that the proposed hybrid strengthening (E3) can be turned to a ductile behavior through further experiments with different configurations.

Comparison of Stab Incision and Eyelid Crease Incision Techniques in Children with Revision Frontalis Sling Surgeries Using Silicone Rods

Ceyhun Arici,İbrahim Bulent Buttanri 대한안과학회 2024 Korean Journal of Ophthalmology Vol.38 No.1

Purpose: To compare stab and eyelid crease incision techniques in revision frontalis sling surgeries using silicone rods. Methods: This retrospective study involved 52 eyes in 48 consecutive pediatric patients who underwent revision frontalis sling surgery between 2008 and 2019. All primary surgeries were performed by making eyelid crease incisions and suturing of silicone rods onto the tarsal plates. The revision surgeries were performed by either making stab incisions over the eyelid through which to pass the silicone rods (group A), or by refixing the same or a new silicone rod to the tarsal plate (group B). The surgical results were compared. Results: The mean follow-up period was 22.4 months (range, 6–62 months) and the mean age of the patients was 6.1 years (range, 1–16 years). There were 28 female and 20 male patients. Surgical success was achieved in 23 of 28 patients (82.1%) in group A, and 12 of 24 patients (50.0%) in group B. The difference between the groups was statistically significant (p = 0.012). Superficial punctate epithelial defects were detected in six group A patients (21.4%) and seven group B patients (29.1%). In group B, lid hematoma occurred in three patients (12.5%) and entropion occurred in three patients (12.5%). The silicone rods were removed from two eyes, and entropion spontaneously resolved in one eye with close follow-up. Conclusions: Using the stab incision technique increases revision frontalis sling surgery success rates when primary surgeries are performed using eyelid crease incisions and suturing silicone rods to the tarsal plates in children.

Numerical evaluation of effects of shear span, stirrup spacing and angle of stirrup on reinforced concrete beam behaviour

Yasin Onuralp Özkılıç,Ceyhun Aksoylu,Musa Hakan Arslan 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.79 No.3

Shear and bending strength of reinforced concrete beams depend on many parameters. It is extremely important to take the necessary precautions in terms of shear in order for the beams to reach their bending capacity. For this reason, it is necessary to determine the effective parameters especially on shear capacity in beams. However, the actual capacity calculation is quite difficult according to regulations that are very conservative in terms of design. Therefore, many experimental studies have been conducted on the shear capacity of the beams. However, this situation is not meaningful in terms of both time and cost, since many experiments will be required to interpret the beam shear behavior, which depends on many parameters. For this reason, the use of advanced software whose verification is performed according to experimental data has become widespread. In this study, a numerical study was carried out on 36 different beam models using the ABAQUS finite element program to examine the effect of the shear span/effective depth (av/d) ratio, stirrup spacing (sw) and the angle of stirrup (α). The results showed that as the av/d increase, the behavior of a shear deficient beam tends to typical bending behavior. Although the effect of stirrup angle on shear capacity is quite high, stirrup angles of 30° and 60° give very similar results. The effect of stirrup spacing is quite limited at relatively high av/d. Stirrups with 90° do not contribute to ductility in beams with high av/d.

Optimum amount of CFRP for strengthening shear deficient reinforced concrete beams

Lokman Gemi,Mohammed Alsdudi,Ceyhun Aksoylu,Şakir Yazman,Yasin Onuralp Özkılıç,Musa Hakan Arslan 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.6

The behavior of shear deficient under-balanced reinforced concrete beams with rectangular cross-sections, which were externally strengthened with CFRP composite along shear spans, was experimentally investigated under vertical load. One of the specimens represents a reference beam without CFRP strengthening and the other specimens have different width/strip spacing ratios (wf/sf). The optimum strip in terms of wf/sf, which will bring the beam behavior to the ideal level in terms of strength and ductility, was determined according to the regulations. When the wf/sf ratio exceeds 0.55, the behavior of the beam shifted from shear failure to bending failure. However, it has been observed that the wf/sf ratio should be increased up to 0.82 in order for the beam to reach sufficient shear reserve value according to the codes. It is also observed that the direction and weight of the CFRP composite are one of the most critical factors and 240 gr/m2 CFRP strips experienced sudden ruptures in the shear span after the cracking of the concrete. It is considered as a deficiency that the empirical shear capacity formulas given for the beams reinforced with CFRP in the regulations do not take into account both direction and weight of CFRP composites.

Evaluation of Hemoglobin A1c Levels in Endometrial Cancer Patients: a Retrospective Study in Turkey

Karaman, Erbil,Karaman, Yasemin,Numanoglu, Ceyhun,Ark, Hasan Cemal Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: Hemoglobin A1c(HgA1c) is a marker of poor gylcemic control and elevation HgA1c is associated with increased risk of many cancers. We aimed to determine the HgA1c levels in endometrial cancer cases and any relationship with stage and grade of disease. Materials and Methods: A retrospective data review was performed between June 2011 and October 2012 at a tertiary referral center in Turkey. The study included 35 surgically staged endometrial cancer patients and 40 healthy controls. Preoperative HgA1c levels drawn within 3 months before surgery were compared. Also the relationships between HgA1c levels and stage, grade and hystologic type of cancer cases were evaluated. Results: The mean HgA1c levels were statistically significantly higher at $6.19{\pm}1.44$ in endometrial cancer cases than the $5.61{\pm}0.58$ in controls (p=0.027). With endometrial cancer cases, the mean HgA1c level was found to be $6.62{\pm}1.40$ for stage I and $6.88{\pm}1.15$ for stages II-IV (p=0.07). The figures were $6.74{\pm}1.65$ for endometrioid and $6.63{\pm}1.41$ for non-endometrioid type tumors (p=0.56). Mean HgA1c levels of $6.72{\pm}1.14$ for grade 1 and $6.62{\pm}1.42$ for grade 2-3 were observed (p=0.57). Conclusions: HgA1c levels in endometrial cancer patients were statistically higher than healthy controls. However, HgA1c did not show any significant correlation with stage, grade and histologic type in endometrial cancer cases.

사우디아라비아의 역내(域內)협력 강화 전략:

신상윤(Shin Sang Yoon),세이훈 마흐무들루(Mahmudlu Ceyhun) 명지대학교 중동문제연구소 2018 중동문제연구 Vol.17 No.2

This study analyzes the oil cooperation between Saudi Arabia and neighbor countries including the five GCC countries, Jordan, Iraq and Yemen. The oil-producing GCC countries’ direct oil trades with Saudi Arabia remain at low levels. However, except for Qatar, their oil cooperation will be strengthened because they maintain close relationships with Saudi Arabia which exerts strong influence on them. Jordan and Iraq are also expected to have stronger oil cooperation with Saudi Arabia. Meanwhile, cooperation with Yemen will be in trouble under the current situation. Saudi Arabia considers forming a cooperative relationship with Israel and fortifying the current cooperation with the U.S. in response to the increasing power of Iran recently enabled by the Syrian civil war. However, this policy might cause serious damage to the legitimacy of Saudi Arabia, particularly with regard to its leading role in the Sunni Islamic world and among the Arab countries. As a result, Saudi Arabia will intend to increase support domestically and regionally. Therefore, in the energy sector, Saudi Arabia will expand both its one-way support and mutual cooperation within the region to retain its leadership position.