Research on effect of the quantity and aspect ratio of steel fibers on compressive and flexural strength of SIFCON

SIFCON (Slurry Infiltrated Fiber Reinforced Concrete) is a composite which occur hardening of the matrix phase, consists of cement, water, mineral additives, fine sand, water reducing plasticizer, and reinforced with high volume fiber (5–20%). The main difference from the high strength concrete (HSC) is the ductile behaviour at failure. However, the brittleness increases with the strength increase in HSC, SIFCON has a ductile behaviour because of the high volume fiber content, low permeability, high durability. Despite fiber content is 2-3% in fiber reinforced concrete, fiber content may be ten times more in SIFCON and ductility is gained. This concrete is suggested to be used in military buildings against explosion, industrial grounds, airports, and bridge feet. In this study, in order to investigate the compressive and flexural strengths of SIFCON, the aspect ratio and fiber volume of steel fibers were chosen as variable and the effects of these parameters on compressive and flexural strengths were investigated. In the study, steel fibers with aspect ratio of 40, 55, 65, and 80 were used in 0, 4, 8 and 12% ratios. The water/binder ratio was kept constant at 0.35. Silica fume is used 10% and water-reducing plasticizer is used 1.5% of cement by weight. 7 and 28 days cured samples were subjected to compressive and flexural tests and the results were compared. As a result of the tests carried out, increases in both the compressive and flexural strengths of SIFCON specimens were determined with increasing fiber volume up to 8%. Strength reductions were observed at higher ratios. In cases where the fiber volume is too high, it has been seen that the strengths were decreased. The reason of strength reduction can be explained by the difficulty of passing ability of mortar between the fibers. The highest strengths were obtained from fibers with the aspect ratio of 80. Increase in the aspect ratio as well as increases in compressive and flexural strengths have been found

Effect of basalt, polypropylene and macro-synthetic fibres on workability and mechanical properties of self-compacting concrete

In this study, the effects of different fibre types on the workability and mechanical properties of self-compacting concrete were investigated. Fresh and hardened properties of self-compacting concrete, different fibre content 0.90, 1.35 and 1.80 kg/m3 were evaluated using basalt, polypropylene and macro synthetic fibres with different fibre lengths of 24, 19 and 40 mm, respectively. The properties of fresh concrete were evaluated in terms of slump flowing, viscosity and flowability. In addition, compressive, flexural and splitting tensile strength were obtained from hardened concrete properties. To characterize mechanical properties 90 specimens were experimentally tested. The results show that the use of fibre reduces the workability of self-compacting concrete. On the other hand, tensile and flexural strength of the self-compacting fibre reinforced concrete increased with increasing fibre content, but it was determined that the fibre addition had no significant effect on the compressive strength

The influence of elevated temperatures on the mechanical properties of polypropylene fiber reinforced concrete

This paper describes the strength of Polypropylene Fiber Reinforced Concrete (PFRC) exposed to the elevated temperatures. In the study, control specimens without any fibers and the concrete specimens with the ratios of 0.30, 0.60, 0.90 and 1.20 kg/m³ polypropylene fibers both in woolen and bar shape fiber have been produced. The specimens have been kept in the laboratory conditions for 28 days. Shortly after the curing period was completed, every group was heated at 23, 150, 300, 450, 600 and 750°C for two hours then the compressive strengths of them were determined. The maximum compressive strength was obtained by the specimens including 0.30 kg/m³ woolen polypropylene. For this group, the compressive strength increase was 8% according to the control specimens. The compressive strengths of bar polypropylene fiber concrete were higher than the wool fibers under elevated temperatures. On the other hand, more compressive strength values are obtained from the control specimens than fiber groups at 600°C temperature. Melting the polypropylene fiber at 500°C formed some pore spaces in concrete and caused reduction of the compressive strength

Kvaliteta usluge konvencionalnih i islamskih banaka u Turskoj

Purpose – The aim of this research study is to determine and compare the service quality of conventional and Islamic banks in Turkey. Design/Methodology/Approach – Stratified sampling method was used to select the sample of respondents for the survey. The data collection phase was carried out online via Google forms and data obtained from 524 participants was used for the analysis. A revised SERVQUAL scale for the banking sector was employed in the research. Findings and implications – The study found service quality expectations of bank customers to be very high, with neither bank type satisfying the expectations of their customers. While conventional banks satisfied 81.2% of their customer expectations, with that proportion falling to 77.8% in the case of Islamic banks, the perception of service quality by customers was found to be higher for conventional banks than for Islamic banks. Especially in the last 20 years, Islamic banking in Turkey has developed at an extremely fast pace. Turkey has become a highly attractive market, particularly for foreign banks focused on Islamic banking. However, although Turkey is a Muslim country, there is not a high preference for Islamic banking. The most important reason behind this is the quality of service offered by the country’s Islamic banks to their customers. This study has demonstrated that the service quality of Turkish banks is unsatisfactory and that improvements to service quality especially by Islamic banks are required, more so than for conventional banks. This research study provides companies seeking to enter the Turkish banking sector with the necessary steps to satisfy the service quality expectations of Turkish customers. Limitations – The main limitations of this study are related to the timeframe and data collection. As service perception changes over time, the service quality of banks can be better evaluated through long-term data collection. This research focused on Turkish banks only, so its results cannot be generalized outside Turkey. Originality – Although certain studies have investigated the service quality of banks in Turkey, no study in the literature has compared the quality of service of conventional and Islamic banks.Svrha – Cilj je istraživanja utvrditi i usporediti kvalitetu usluge konvencionalnih i islamskih banaka u Turskoj. Metodološki pristup – Pri odabiru uzorka korištena je metoda stratificiranog uzorkovanja. U istraživanju je uporabljena za bankarski sektor prilagođena SERVQUAL ljestvica. Prikupljanje podataka provedeno je online putem Google obrasca, a za analizu su korišteni podatci prikupljeni od 524 ispitanika. Rezultati i implikacije – Uočeno je da su očekivanja kvalitete usluge korisnika usluga banke vrlo visoka te da obje vrste banaka ne ispunjavaju njihova očekivanja. Dok su konvencionalne banke uspjele zadovoljiti 81.2 % očekivanja korisnika, kod islamskih banaka taj omjer pada na 77.8 %. Utvrđeno je i da je percepcija kvalitete usluge korisnika viša kod konvencionalnih nego kod islamskih banaka. U posljednjih 20 godina u Turskoj se islamsko bankarstvo vrlo brzo razvija. Turska je postala vrlo atraktivno tržište, posebno za inozemne banke usmjerene na islamsko bankarstvo. No, iako je Turska muslimanska zemlja, preferiranje islamskih banaka nije visoko. Najvažniji razlog za takvu situaciju temelji se na kvaliteti usluge koju islamske banke nude svojim korisnicima. Istraživanje je pokazalo da kvaliteta usluge banaka u Turskoj nije zadovoljavajuća, a kvalitetu usluge više od konvencionalnih banaka posebno bi trebale poboljšati islamske banke. Istraživanje posebno pomaže poduzećima koja razmišljaju o ulasku na tursko bankarsko tržište da bi se vidjelo što je potrebno poduzeti za zadovoljavanje očekivanja turskih korisnika od kvalitete usluge. Ograničenja – Glavna ograničenja istraživanja vezana su uz vremenski okvir i prikupljanje podataka. Percepcija usluge mijenja se s vremenom, tako da se kvaliteta usluge banaka može bolje ocijeniti dugotrajnijim prikupljanjem podataka. Istraživanje je ograničeno na turske banke pa su i rezultati procijenjeni samo za Tursku. Doprinos – Iako postoje prethodna istraživanja o kvaliteti usluge banaka u Turskoj, ne postoji istraživanje koje uspoređuje kvalitetu usluge konvencionalnih i islamskih banaka

The Marble King

30 pagesBitirme tezi olarak sunduğum Mermer Kral isimli çalışma İstanbul hakkında bir üçlemenin ikinci ayağını oluşturmakta. Üç filmin de amacı şehri değil ondan çıkıldığı, onun kaybedildiği anı anlatmak. Daha da netleştirmek gerekirse şehre, ondan çıkıldığı noktadan ulaşmak. Formüle edecek olursam, ilk film çocukluğun kaybını anlatır, ikinci film gençliğin kaybına değinir.The Marble King is the second film of a trilogy on Istanbul. The common goal of this trilogy is to narrate not the city itself but the moment when it is lost. The first film narrates the loss of childhood, the second narrates that of the youth in the city

(E)-2-[(4-Chloro­phen­yl)imino­meth­yl]-4-(trifluoro­meth­oxy)phenol

The title compound, C14H9ClF3NO2, crystallizes in a phenol–imine tautomeric form, with a strong intra­molecular O—H⋯N hydrogen bond. The dihedral angle between the two benzene rings is 47.62 (9)°. In the crystal, mol­ecules are linked into chains along the c axis by C—H⋯O hydrogen bonds, and weak C—H⋯π inter­actions involving both benzene rings are also observed

The Effect of Solution Focused Brief Therapy Approach Based Group Guidance Program on Self-Efficacy Beliefs

Bireylerin bir şeyi başarabileceğine dair inancı olarak tanımlanan öz-yeterlik birçok faktör üzerinde etkilidir. Yüksek öz-yeterlik algısı bireylerin performanslarını pozitif yönde etkiler. Bu nedenlerle bu araştırmanın amacı, çözüm odaklı kısa süreli yaklaşıma dayalı grup rehberliği programının 8.sınıf öğrencilerinin öz-yeterlik düzeylerine olan etkisini incelemektir. Araştırmaya İstanbul ili Bakırköy ilçesinde öğrenim görmekte olan ortaokul 8. sınıf öğrencisi 145 kişi katılmıştır. Katılımcılara Genel Öz-yeterlik Ölçeği uygulanmıştır. Katılımcılar arasından uygun örnekleme yöntemiyle, deney ve kontrol gruplarına 10’ar kişi seçilmiştir. Deney grubunu oluşturulan birey-lere araştırmacı tarafından hazırlanan altı oturumluk çözüm odaklı kısa süreli grup rehberliği programı uygulanmıştır. Kontrol grubundaki bireylere ise hiçbir işlem uygulanmamıştır. Araştır-ma 2x3’lük desen kullanılmıştır. Elde edilen veriler ANOVA Tekniği ile analiz edilmiştir. Araştırma sonucunda uygulanan programın katılımcıların öz-yeterlik düzeylerini arttırdığı ve bu durumun izleme ölçümlerinde de korunduğu görülmüştür.Self-efficacy, defined as beliefs that individuals can achieve something, is influential on many things. Having a high self-efficacy perception may have positive effect on individuals' performanc-es. Therefore, the aim of current study was to investigate the effect of Solution- Focused Brief Ther-apy Approach Based Group Guidance Program on students’ self-efficacy beliefs. Study participants were selected among 145 8th grade middle school students in Bakırköy, Istanbul. In order to collect the data the General Self-Efficacy Scale was administered. Convince sampling was used to select 20 students, 10 each in experimental group and control group. A six session Solution- Focused Brief Approach Based Group Guidance Program developed by the researcher was applied to the experi-mental group. Any intervention was not applied to participants in control group. The research used the 2x3 factorial design experiment method. A two-way analysis of variance (ANOVA) with repeated measures was conducted to evaluate the effect of guidance program. As a result of the study revealed that the Solution Focused Brief Approach Based Group Guidance Program was significantly effective in increasing the self-efficacy beliefs' of the participants in experimental group. The effect of the program lasted during the follow-up tests

GD Anadolu Orojenik Kuşağı ofiyolitlerinin manto peridotitleri bileşimleri ve petrolojisi: Ana element, iz element jeokimyası ve mineral kimyası

The aim of this study is to reveal mantle processes such as tectonic environment, partial melting degree and melt-rock interactions of mantle peridotite (harzburgite and dunite) of Kızıldağ, Koçali and Guleman ophiolites outcropping in South Eeast Anatolia Ophiolite Belt. For this purpose, geochemical analyses of whole rock (main oxide, trace element, Rare Earth Element) and mineral base (mineral chemistry) in mantle peridotite samples which are generally harzburgite and dunite, show different degrees of serpentinization, were carried out in various laboratories. As a result of all of this study, the clinopyroxene minerals of harzburgite and dunite type rocks belonging to the mantle peridotites of the ophiolites are extremely depleted. So it seems that these samples have very low Al2O3 (% 0−4,93 %wt.) and CaO (%0.10−2.38 %wt.) and high MgO (39.27−49.58 %wt.) content in whole rock. In addition, the fact that these rocks have high Cr# in spinels is interpreted because the mantle peridotites contain moderate to high degrees of partial melting residues. On the other hand, enrichment of Al2O3 and CaO contents and decrease of Cr# values of spinels in proportion to increasing clinopyroxene abundances of some mantle peridotite samples result from lower degree melting residues than other samples. Enrichment of mantle peridotites, especially light REE and Large Ion Lithophile Elements (LILE), is a result of metasomatism with melts having different composition in subduction zones. As a result, especially considering the results of mineral chemistry, trace element and RRE analysis, it is thought that the mantle peridotites of the ophiolites are the residual rocks which form the subject of the project are formed in the mid-ocean ridge environment and then exposed to the second phase depletion in the subduction zone (forearc environment) and in this period, it is thought that metasomatized by slab derived melt in various composition

Effect of Polypropylene Fiber on Workability and High Temperature Resistance of Self-Compacting Concrete

Konvansiyonel betona kıyasla yüksek işlenebilirlik, düşük işçilik maliyeti ve yüksek dayanım gibi avantajlar sağlayan kendiliğinden yerleşen beton (KYB) yüksek performanslıdır. Bu çalışma ile kendiliğinden yerleşen betonlarda, polipropilen lif miktarının (0,25; 0,50; 0,75 ve 1,00 kg/m3 ) taze betonun işlenebilirliği ve sertleşmiş betonların da bazı mekanik dayanım özellikleri üzerindeki etkisi belirlenerek; farklı sıcaklıkların (25, 250, 500 ve 750 °C) sertleşmiş KYLB’lar üzerindeki etkilerinin araştırılması amaçlanmaktadır. Sertleşmiş numuneler 25, 250, 500 ve 750°C sıcaklıklarına tabi tutulmuştur. Ayrıca, numunelerin boşluk yapıları hakkında fikir edinmek için ultrases geçiş hızı ölçümleri gerçekleştirilmiştir. Çalışma sonucunda, polipropilen lif miktarının artması ile kendiliğinden yerleşen betonun akıcılığının olumsuz yönde etkilendiği, basınç dayanımının değişmediği ve çekme dayanımının olumlu yönde değiştiği gözlenmiştir. 500ºC ve üzeri sıcaklıklarda, beton basınç dayanımının ve ultrases geçiş hızlarının azaldığı tespit edilmiştir. Sıcaklık arttıkça polipropilen liflerin eridiği ve bunun sonucu olarak betonda oluşan boşlukların artması ile dayanımının azaldığı gözlenmiştir. 750 ºC’de en fazla mukavemet kaybı görülmüştür.Self-consolidating concrete (SCC) that provides advantages such as high workability, low labor cost and high strength compared to conventional concrete has high performance. The aim of this study is to determine the effect of polypropylene fiber amount (0.25; 0.50; 0.75 and 1.00 kg/m3 ) on the workability and strength properties of fiber reinforced self-consolidating concretes. Hardened samples were subjected to temperatures of 25, 250, 500 and 750 °C. In addition, ultrasound pulse velocity measurements were performed to obtain an idea about the void structures of the samples. As a result of the study, it was observed that as the amount of polypropylene fiber increased, the fluidity of the self-consolidating concrete negatively affected, the compressive strength did not change and the tensile strength changed positively. It was determined that the concrete compressive strength and ultrasound transition velocities decreased in the temperatures of 500ºC and above. It has been observed that as the temperature increased, the polypropylene fibers melted and as a result of which, with the increase of gaps in concrete, its strength decreases. The highest loss of strength was observed at 750ºC

Human shaped stone sculptures and balbals belonging to early period Turkish Culture in Ormanlı Village of Şenkaya District of Erzurum

Doğu Anadolu Bölgesi, Avrasya’dan Anadolu’ya gelen kavimler için ilk durak olmuştur. Dağlık bir coğrafya olan bölgede bulunan geniş platolar ve su kaynakları eskiçağlardan itibaren bu bölgeyi özellikle küçükbaş hayvancılıkla geçinen atlı göçer kültürler için cazibe merkezi haline getirmiştir. Orta Asya’dan Anadolu’ya girmek isteyen bu kavimler için Hazar Denizi tabii bir engel olmuşsa da bu kültürler kuzeyde Kafkas güneyde ise Zagros geçitlerini kullanarak Anadolu’ya girmişlerdir. Bu kültürler arkalarında kurganlar-mezarlar, damgalar-enler, runik yazılar, kaya resimleri, toponimler ve taş heykeller-balballar gibi birçok kültür unsuru bırakmışlardır. Makalede bu unsurlar arasında yer alan Şenkaya Taş heykelleri ve balbalları incelenmiştir. Taş heykeller betimlenerek motifleri değerlendirilmiş, önce kendi içlerinde sonra da Anadolu ve Avrasya taş heykel geleneği ile kıyaslaması yapılarak tarihlendirilmiştir.The Eastern Anatolia Region has been the first stop for the tribes coming to Anatolia from Eurasia. The wide plateaus and water resources in the region, which is a mountainous geography, have made this region a center of attraction for equestrian nomadic cultures that live on sheep and goats since ancient times. Although the Caspian Sea was a natural obstacle for these tribes who wanted to enter Anatolia from Central Asia, these cultures entered Anatolia using the Caucasus in the north and the Zagros in the south. These cultures left behind many cultural elements such as kurgans-graves, stamps-heaps, runic writings, rock paintings, toponyms and stone statues-balbals. In the article, Şenkaya Stone statues and balbals, which are among these elements, were examined. Stone sculptures were depicted and their motifs were evaluated, and then they were dated by comparing them with the Anatolian and Eurasian stone sculpture tradition