Fire resistance of hybrid fiber reinforced SCC: Effect of use of polyvinyl-alcohol or polypropylene with single and binary steel fiber

Kazim Turk,Ceren Kina,Esma Balalan Techno-Press 2023 Advances in concrete construction Vol.16 No.1

This study presents the experimental results performed to evaluate the effects of Polyvinyl-alcohol (PVA) and Polypropylene (PP) fibers on the fresh and residual mechanical properties of the hybrid fiber reinforced SCC before and after the exposure of 250℃, 500℃ and 750℃ temperatures. The compressive and splitting tensile strength, modulus of rupture (MOR), ultrasonic pulse velocity (UPV) as well as toughness and weight loss were investigated at different temperatures. PVA and PP fibers were added into SCC mixtures having only macro steel fiber and also having binary hybridization of both macro and micro steel fiber. The results showed that the use of micro steel fiber replaced by macro steel fiber improved the fresh and hardened properties compared to the use of only macro steel fiber. Moreover, it was emphasized that PVA or PP enhanced the residual flexural performance of SCC, generally, while it negatively influenced the workability, weight loss, UPV and the residual strengths with regards to the use of single steel fiber and binary steel fiber hybridization. Compared to the effect of synthetic fibers, PP had slightly more positive effect in the view of workability while PVA enhanced the residual mechanical properties more.

Effect of Fly Ash and Silica Fume on Compressive Strength, Sorptivity and Carbonation of SCC

Kazim Turk,Mehmet Karatas,Tahir Gonen 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

In this paper, ASTM C 618 Class F Fly Ash (FA) at 25%, 30%, 35% and 40% and Silica Fume (SF) at 5%, 10%, 15% and 20%replacement of Portland Cement (PC) CEM I 42.5 in SCC was used to evaluate the effect of types and quantity of powder additions on compressive strength and permeations properties of SCC. To this end, eight types of SCC were designed, in comparison with Vibrated Traditional Concrete (VTC). The results indicated that SCC specimens with SF15 had the highest compressive strength with 73.87 MPa for 130 days. The sorptivity values of SCC specimens with FA and SF were lower than those of VTC specimens regardless of type and quantity of powder additions. On the other hand, the carbonation resistance of VTC was higher than that of SCC specimens containing both SF and FA for all accelerated carbonation periods. Consequently, it can be said that type and quantity of powder additions had an important effect on the correlation among the compressive strength and permeation properties of SCC.

Influence of loading condition and reinforcement size on the concrete/reinforcement bond strength

Kazim Turk,Sinan Caliskan,M. Sukru Yildirim 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.19 No.3

Colonic Metastasis from Carcinoma of the Breast that Mimicks a Primary Intestinal Cancer

Kazim Uygun,Zafer Kocak,Semsi Altaner,Irfan Cicin,Fusun Tokatli,Cem Uzal 연세대학교의과대학 2006 Yonsei medical journal Vol.47 No.4

Although the lung, liver, or bones are the most common location for distant metastases in breast cancer patients, metastases to the intestinal tract are very rarely recognized in the clinic. We will present an unusual case of colonic metastasis from a carcinoma of the breast that mimics a primary intestinal cancer, along with a through review of English language medical literature. Despite the fact that isolated gastrointestinal (GI) metastases are very rare and much less common than benign disease processes or second primaries of the intestinal tract in patients with a history of breast cancer, metastatic disease should be given consideration whenever a patient experiences GI symptoms.

Thickness of cumulus cell layer is a significant factor in meiotic competence of buffalo oocytes

Kazim R. Chohan,Hassan M.Warriach 대한수의학회 2004 Journal of Veterinary Science Vol.5 No.3

This study evaluated the meiotic competence of buffalo oocytes with different layers of cumulus cells. A total of 588 oocytes were collected from 775 ovaries averaging 0.78 oocytes per ovary. Oocytes with homogenous cytoplasm (n = 441) were selected for in vitro maturation (IVM) and divided into four groups based on their cumulus morphology: a) oocytes with ≥ = 3 layers of cumulus cells, b) 1-2 layers of cumulus cells and oocytes with partial remnants or no cumulus cells to be cocultured c) with or d) without cumulus cells. Oocytes in all four groups were matured in 100 μL drop of TCM-199 supplemented with 10 μg/mL follicle stimulating hormone (FSH), 10 μg/mL luteinizing hormone (LH), 1.5 μg/mL estradiol, 75 μg/mL streptomycin, 100 IU/mL penicillin, 10 mM Hepes and 10% FBS at 39oC and 5% CO2 for 24 hours. After IVM, cumulus cells were removed from oocytes using 3 mg/mL hyaluronidase, fixed in 3% glutaraldehyde, stained with DAPI and evaluated for meiotic competence. The oocytes with ≥ = 3 layers of cumulus cells showed higher maturation rates (p < 0.05: 64.5%) than oocytes with partial or no cumulus cells (8.6%) and oocytes co-cultured with cumulus cells (34.5%) but did not differ from oocytes having 1-2 layers of cumulus cells (51.4%). The degeneration rates were higher (p < 0.05) for oocytes with partial or no cumulus cells (51%) than rest of the groups (range: 13.8% to 17.4%). These results suggest that buffalo oocytes with intact layers of cumulus cells show better IVM rates than oocytes without cumulus cells and the co-culture of poor quality oocytes with cumulus cells improves their meiotic competence.

Predictors of Intra-Aortic Balloon Pump Insertion in Coronary Surgery and Mid-Term Results

Kazim Ergüneş,Ismail Yurekli,Ersin Celik,Ufuk Yetkin,Levent Yilik,Ali Gurbuz 대한흉부외과학회 2013 Journal of Chest Surgery (J Chest Surg) Vol.46 No.6

Background: We aimed to investigate the preoperative, operative, and postoperative factors affecting intra-aortic balloon pump (IABP) insertion in patients undergoing isolated on-pump coronary artery bypass grafting (CABG). We also investigated factors affecting morbidity, mortality, and survival in patients with IABP support. Methods: Between January 2002 and December 2009, 1,657 patients underwent isolated CABG in İzmir Katip Celebi University Atatürk Training and Research Hospital. The number of patients requiring support with IABP was 134 (8.1%). Results: In a multivariate logistic regression analysis, prolonged cardiopulmonary bypass time and prolonged operation time were independent predictive factors of IABP insertion. The postoperative mortality rate was 35.8% and 1% in patients with and without IABP support, respectively (p=0.000). Postoperative renal insufficiency, prolonged ventilatory support, and postoperative atrial fibrillation were independent predictive factors of postoperative mortality in patients with IABP support. The mean follow-up time was 38.55±22.70 months and 48.78±25.20 months in patients with and without IABP support, respectively. The follow-up mortality rate was 3% (n=4) and 5.3% (n=78) in patients with and without IABP support, respectively. Conclusion: The patients with IABP support had a higher postoperative mortality rate and a longer length of intensive care unit and hospital stay. The mid-term survival was good for patients surviving the early postoperative period.

Effect of Reproductive Status on In Vitro Developmental Competence of Bovine Oocytes

Kazim R. Chohan,Alan G. Hunter 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.1

On a group closely related with the automorphic Langlands group

Kazim Ilhan Ikeda 대한수학회 2020 대한수학회지 Vol.57 No.1

Let $L_K$ denote the hypothetical automorphic Langlands gr\-oup of a number field $K$. In our recent study, we briefly introduced a certain unconditional non-commutative topological group $\mathscr {WA}_K^{\underline{\varphi}}$, called the Weil-Arthur id\`ele group of $K$, which, assuming the existence of $L_K$, comes equipped with a natural topological group homomorphism $\mathsf{NR}_K^{\underline\varphi^{\mathrm{Langlands}}}: \mathscr {WA}_K^{\underline{\varphi}}\rightarrow L_K$ that we called the ``Langlands form'' of the global non-abelian norm-residue symbol of $K$. In this work, we present a detailed construction of $\mathscr {WA}_K^{\underline{\varphi}}$ and $\mathsf{NR}_K^{\underline\varphi^{\mathrm{Langlands}}}: \mathscr {WA}_K^{\underline{\varphi}}\rightarrow L_K$, and discuss their basic properties.

NOTE ON BERTRAND B-PAIRS OF CURVES IN MINKOWSKI 3-SPACE

( Kazim Ilarslan ),( Ali Ucum ),( Nihal Kilic Aslan ),( Emilija Nesovic ) 호남수학회 2018 호남수학학술지 Vol.40 No.3

In this paper, we define null Cartan and pseudo null Bertrand curves in Minkowski space E according to their Bishop frames. We obtain the necessary and sufficient conditions for pseudo null curves to be Bertand B-curves in terms of their Bishop curva-tures. We prove that there are no null Cartan curves in Minkowski 3-space which are Bertrand B-curves, by considering the cases when their Bertrand B-mate curves are spacelike, timelike, null Cartan and pseudo null curves. Finally, we give some examples of pseudo null Bertrand B-curve pairs.

Freeze-thaw resistance and sorptivity of self-compacting mortar with ternary blends

Kazim Turk,Ceren Kina 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.2

This paper investigated the influence of binary and ternary blends of mineral admixtures in self-compacted mortar (SCM) on the fresh, mechanical and durability properties. For this purpose, 25 mortar mixtures were prepared having a total binder content of 640 kg/cm3 and water/binder ratio between 0.41 and 0.50. All the mixtures consisted of Portland cement (PC), fly ash (FA) and silica fume (SF) as binary and ternary blends and air-entrained admixture wasn’t used while control mixture contained only PC. The compressive and tensile strength tests were conducted for 28 and 91 days as well as slump-flow and Vfunnel time tests whilst freeze-thaw (F-T) resistance and capillary water absorption tests were made for 91-day. Finally, in general, the use of SF with FA as ternary blends improved the tensile strength of mortars at 28- and 91-day while the use of SF15 with FA increased the compressive strength of the mortars compared to binary blends of FA. SCM mixtures with ternary blends had lower the sorptivity values than that of the mortars with binary blends of FA and the control mixture due to the beneficial properties of SF while the use of FA with SF as ternary blends induced the F-T resistance enhancement.