The investigation of seismic performance of existing RC buildings with and without infill walls

Hakan Dilmac,Hakan Ulutas,Hamide Tekeli,Fuat Demir 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.22 No.5

One of the important factors is the infill walls in the change of the structural rigidity, ductility, dynamic and static characteristics of the structures. The infill walls are not generally included in numerical analysis of reinforced concrete (RC) structural system due to lack of suitable theory and the difficulty of calculating the recommended models. In seismic regions worldwide, the residential structures are generally RC buildings with infill wall. Therefore, understanding the contribution of the infill walls to seismic performance of buildings may have a vital importance. This paper investigates the effects of infill walls on seismic performance of the existing RC residential buildings by considering requirements of the Turkish Earthquake Code (TEC). Seismic performance levels of residential RC buildings with and without walls in high-hazard zones were determined according to the nonlinear procedure given in the code. Pushover curves were obtained by considering the effect of masonry infill walls on seismic performance of RC buildings. The analysis results showed that the infill walls beneficially effected to the rigidity, roof displacements and seismic performance of the building.

Gene network and canonical pathway analysis in prostatecancer: a microarray study

Hakan Savli,Attila Szendrӧi,Imre Romics,Balint Nagy 생화학분자생물학회 2008 Experimental and molecular medicine Vol.40 No.2

The molecular mechanism playing a role in the development of prostate cancer (PCA) is not well defined. We decided to determine the changes in gene expression in PCA tissues and to compare them to those in noncancerous samples. Prostate tissue samples were collected by needle biopsy from 21 PCA and 10 benign prostate hyperplasic (BPH) patients. Total RNA was isolated, cDNA was synthesized, and gene expression levels were determined by microarray method. In the progression to PCA, 738 up-regulated and 515 downregulated genes were detected in samples. Analysis using Ingenuity Pathway Analysis (IPA) software revealed that 466 network and 423 functions-pathways eligible genes were up-regulated, and 363 network and 342 functions-pathways eligible genes were down-regulated. Up-regulated networks were identified around IL-1β and insulin-like growth factor-1 (IGF-1) genes. The NFKB gene was centered around two upand down-regulated networks. Up-regulated canonical pathways were assigned and four of them were evaluated in detail: acute phase response, hepatic fibrosis, actin cytoskeleton, and coagulation pathways. Axonal guidance signaling was the most significant down-regulated canonical pathway. Our data provide not only networks between the genes for understanding the biologic properties of PCA but also useful pathway maps for future understanding of disease and the construction of new therapeutic targets. The molecular mechanism playing a role in the development of prostate cancer (PCA) is not well defined. We decided to determine the changes in gene expression in PCA tissues and to compare them to those in noncancerous samples. Prostate tissue samples were collected by needle biopsy from 21 PCA and 10 benign prostate hyperplasic (BPH) patients. Total RNA was isolated, cDNA was synthesized, and gene expression levels were determined by microarray method. In the progression to PCA, 738 up-regulated and 515 downregulated genes were detected in samples. Analysis using Ingenuity Pathway Analysis (IPA) software revealed that 466 network and 423 functions-pathways eligible genes were up-regulated, and 363 network and 342 functions-pathways eligible genes were down-regulated. Up-regulated networks were identified around IL-1β and insulin-like growth factor-1 (IGF-1) genes. The NFKB gene was centered around two upand down-regulated networks. Up-regulated canonical pathways were assigned and four of them were evaluated in detail: acute phase response, hepatic fibrosis, actin cytoskeleton, and coagulation pathways. Axonal guidance signaling was the most significant down-regulated canonical pathway. Our data provide not only networks between the genes for understanding the biologic properties of PCA but also useful pathway maps for future understanding of disease and the construction of new therapeutic targets.

Investigation of the effects of geometrical parameters on heat transfer from buried finned pipes

Hakan Demir,Ahmet Koyun,S. Özgür Atayılmaz,Özden Ağra,Ahmet Selim Dalkılıç 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.8

Heat transfer from finned pipes buried in the soil has been investigated using experimental, analytical and numerical techniques. The experimental setup consists of a ground source heat pump system and two separate ground heat exchangers. Constant surface temperature approach based on Carslaw and Jaeger’s theory study was used for calculating the heat transfer from the pipes analytically. The problem was modeled and solved using a CFD program numerically. Effects of the fin number, fin length and simulation time on the heat transfer rate have been investigated and compared with bare tube. A modified analytical formula was also proposed for finned pipes in this study.

Argon Green Laser for Valsalva Retinopathy Treatment and Longterm Follow-up of the Internal Limiting Membrane Changes in Optical Coherence Tomography

Hakan Tirhis,Cagatay Caglar,Pelin Yilmazbas,Mustafa Alparslan Anayol,Mehmet Ali Şekeroğlu 대한안과학회 2015 Korean Journal of Ophthalmology Vol.29 No.6

The use of definitive implant abutments for the fabrication of provisional crowns: a case series

Hakan Bilhan,Onur Geckili,Emre Mumcu 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.5

Purpose: The anterior region is a challenge for most clinicians to achieve optimal esthetics with dental implants. The provisional crown is a key factor in the success of obtaining pink esthetics around restorations with single implants, by soft tissue and inter-proximal papilla shaping. Provisional abutments bring additional costs and make the treatment more expensive. Since one of the aims of the clinician is to reduce costs and find more economic ways to raise patient satisfaction, this paper describes a practical method for chair-side fabrication of non-occlusal loaded provisional crowns used by the authors for several years successfully. Methods: Twenty two patients (9 males, 13 females; mean age, 36,72 years) with one missing anterior tooth were treated by using the presented method. Metal definitive abutments instead of provisional abutments were used and provisional crowns were fabricated on the definitive abutments for all of the patients. The marginal fit was finished on a laboratory analogue and temporarily cemented to the abutments. The marginal adaptation of the crowns was evaluated radiographically. Results: The patients were all satisfied with the final appearance and no complications occurred until the implants were loaded with permanent restorations. Conclusions: The use of the definitive abutments for provisional crowns instead of provisional abutments reduces the costs and the same results can be obtained.

Swedish Explorers, Missionaries and Collectors -The History of some Central Asian Collectors and their Collections in the National Museum of Ethnography, Stockholm

( Hakan Wahlquist ) 중앙아시아학회 2000 中央아시아硏究 Vol.5 No.-

Determination of concrete quality with destructive and non-destructive methods

Hakan Kibar,Turgut Öztürk 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.3

In this study, the availability of Schmidt hammer has been investigated as a reliable method to determine the quality of concrete in irrigation networks. For this purpose, the 28-day compressive strength of concrete material used in the construction irrigation channel of Bafra lowland, which is one of the most fertile plains in Turkey was examined by means of concrete compression and as well as concrete Schmidt hammer in laboratory conditions. This study was carried out on cylindrical samples to represent the everyday concrete party (150 m3) produced by contractor firm as 3 replications. The statistical analysis of experimental data showed that the correlations between the values of 28-day compressive strength of Schmidt hammer and the rebound number was found to be 0.98. Differences of the compressive strength between compression testing and Schmidt hammer were statistically significant at P<0.01. In this context, it was found that the reliability of compressive strength of the concrete compression test are excellent, also the reliability of compressive strength of Schmidt hammer are fair in assessing the quality of concrete irrigation channels.

Dynamic behavior investigation of scale building renovated by repair mortar

Hakan Başaran 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.16 No.4

The objective of this study was to examine the effect of repair mortar on the dynamic properties such as natural frequencies, mode shape and damping ratios of two story single span scale reinforced concrete building. To this end, two story single span scale reinforced concrete building having dimensions of 150 cm (width), 150 cm (length) and 135 cm (height) was constructed. Workmanship defects such as separation of material, faulty vibration application and bad gradation of the structure were properly evaluated. Dynamic properties of damaged structure were experimentally determined using Operational Modal Analysis (OMA). Detected defects in the structure were fixed by plastering with repair mortar. Dynamic properties of repaired structure were reevaluated by using the OMA method. Finite element software called Abaqus was used to numerically determine dynamic properties of the structure. Structure modeled as solid was subjected to Linear Perturbation Frequency Method. The changes in dynamic properties of structure after the repair process were comparatively studied by evaluating experimental and numerical results.

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.

Experimental and numerical investigation of walls strengthened with fiber plaster

Hakan Basaran,Ali Demir,Muhiddin Bagcı,Sefa Ergun 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.56 No.2

The topic of this study is to investigate behaviors of masonry walls strengthened with reinforced fiber plaster under diagonal tensile loads. Full blend brick 100×50×30 mm in dimensions were used to make masonry walls with dimensions of 400×400×100 mm. Three different samples were manufactured by plastering masonry walls with traditional style, with 3% polypropylene or with 5% steel fiber. All the samples were tested using ASTM 1391- 81 standards. The propagation of damage on samples caused by diagonal tensile load was observed and load-displacement graphs were plotted for each sample. A finite element software (ABAQUS) was used to obtain numerical values for all samples and crack patterns and load-displacement responses were obtained. Experimental and numerical results were compared.