Yazarlar
- Dokuz, Abdurrahman(2)
- Tanyolu, Erkan(2)
- Acar, Ramazan(1)
- Arslan, M.(1)
- Aslan, Z.(1)
- Bayram, B.(1)
- Bayram, Bahri(1)
- Bektaş, Osman(1)
- Doǧangün, A.(1)
- Doǧangün, Adem(1)
- Eyüboǧlu, Yener(1)
- Genç, Salim(1)
- Güler, O.(1)
- Güler, Olcay(1)
- Jacoby, Wolfgang R.(1)
- Kandemir, Raif(1)
- Karadeniz, S.(1)
- Karsli, Orhan(1)
- Livaoǧlu, R.(1)
- Livaoǧlu, Ramazan(1)
- Maden, Nafiz(1)
- Metin, J.(1)
- Metin, Jale(1)
- Oguzhan, B.(1)
- Olmez, B.(1)
- Sargin, M.(1)
- Tuluk, Ö.Iskender(1)
- Yanar, M.(1)
- Yanar, Mete(1)
- Yilmaz, Cemil(1)
- Yilmaz, T.(1)
- Özer, Rahşan(1)
- Şeren, Aysel(1)
Yayınlar
- MakaleYalnız künye2006Effects of feeding acidified milk replacer on the growth, health and behavioural characteristics of holstein Friesian calves
Yanar, Mete; Güler, Olcay; Bayram, Bahri; Metin, Jale
The objective of this study was to compare the performances of calves fed acidified milk replacer (AMR) or sweet (regular) milk replacer (SMR) at 8% of birth weight. Twenty- one calves (10 males, 11 females) were offered replacers reconstituted to 12% of dry matter over 5 weeks. In the group fed AMR, daily body weight gains of calves at the different stages of growth were comparable to those for calves fed SMR. In the preweaning period, calves offered AMR had similar dry matter intakes from starter, milk replacer and dry hay as well as total intake as those fed SMR. In the postweaning phase, total dry matter intakes of calves offered AMR and SMR were not statistically different. The overall feed efficiency ratios of AMR- fed calves were better (P < 0.05) than those of SMR- fed calves. Calf faecal consistency score (P < 0.05) and percent days with scours (P < 0.01) of calves offered AMR were significantly lower than those fed SMR for days 4 to 17. AMR-fed calves needed a longer time (P < 0.01) to consume the daily amount of replacer than SMR- fed calves. The calves fed AMR also took a significantly (P < 0.05) greater number of days to learn to drink milk replacer from an open pail without help than calves consuming SMR. In conclusion, it is suggested that the growth performance and feed efficiency characteristics of calves reared under the new feeding system with AMR were not adversely affected, but the incidence of scours of the young calves was dramatically reduced.
- MakaleYalnız künye2006Performance and health of dairy calves fed limited amounts of acidified milk replacer
Güler, O.; Yanar, M.; Bayram, B.; Metin, J.
To compare growth performance of Brown Swiss calves fed acidified milk replacer (AMR) at 8% of birth weight, 20 newborn calves were reared under a new calf-feeding programme. Body weights, total weight gains and gains in body measurements, feed intake and feed efficiency values determined at different stages of growth of AMR-fed calves were comparable to those of calves fed sweet milk replacer (SMR). Faecal consistency scores and percent days with diarrhoea of calves offered AMR from four to 35 days of age were respectively 0.4 and 19.1% lower than those fed SMR. Most of the bebavioural parameters studied were not unfavourably influenced by acidification of the replacer. In conclusion, growth, feed intake and feed efficiency characteristics of Brown Swiss calves fed AMR or SMR were not different from each other. However, incidence of diarrhoea of the young calves was decreased and health status of the calves was improved with the feeding of acidified milk.
- MakaleYalnız künye2006Geochemical constraints on the provenance, mineral sorting and subaerial weathering of Lower Jurassic and Upper Cretaceous clastic rocks of the eastern Pontides, Yusufeli (Artvin), NE Turkey
Dokuz, Abdurrahman; Tanyolu, Erkan
An integrated petrographic and geochemical study of the shales and sandstones of Early Jurassic and Late Cretaceous age in the Yusufeli area (Turkey) was carried out to obtain more information on their provenance, sedimentological history and tectonic setting, as well as to evaluate the influence of weathering, hydraulic sorting and recycling processes upon source-rock signature. Depending on their matrix and mineralogical content the Lower Jurassic sandstones are identified as arkosic arenite and wacke, while the Upper Cretaceous sandstones are defined as lithic arenite and wacke. Elemental ratios such as La/Sc, Cr /Ni, Co/Th, Th/Sc and Cr/Th indicate a mafic source for the marjority of each of the sandstone sequences. However, in several samples, high Th/Sc and low Cr/Th ratios suggest a contribution from a felsic source. Using element-ratio diagrams, all of the samples plot along a curve consistent with a two-component mixing model, consisting of a dominant mafic and a subordinate felsic source. The relatively low Cr/Ni ratios provide no support for significant amounts of ultramafic lithologies in the source area. The lower trace-element contents of the studied sandstones in relation to post-Archean Australian shales (PAAS), which are representative of the composition of the upper continental crust, indicate that recycling processes in their source areas were probably less intense than those of the PAAS. The more LREE-depleted patterns of the shales relative to sandstones likely do not reflect changes in source-area composition but, rather, variations in mineral sorting, chemical weathering and/or sediment recycling. Chemical index of alteration (CIA) indices observed in the Lower Jurassic and Upper Cretaceous sediments (average of 53 & 46, respectively) suggest that their source area underwent moderate degrees of chemical weathering processes. However, an upward increase in the values of the CIA indices in the Lower Jurassic profiles may indicate that the source area gradually underwent more intense chemical weathering, possibly due to climatic and/or tectonic variations. On the other hand, an upward decrease in the CIA indices of the Upper Cretaceous profiles generally demonstrate that the sediments were derived from a relatively less-weathered source terrain, reflecting an increased erosion rate likely due to increasing tectonic activity. The compositional immaturity of the analysed sandstone samples is typical of subduction-related environments, and their SiO2/Al2O3 and K2O/Na2O ratios and Co, Sc, Th and Zr contents reflect their oceanic and continental-arc settings.
- MakaleYalnız künye2006Traditional wooden buildings and their damages during earthquakes in Turkey
Doǧangün, Adem; Tuluk, Ö.Iskender; Livaoǧlu, Ramazan; Acar, Ramazan
Wood is one of the oldest structural materials used in structures in many parts of the World. Woodframe buildings were also commonly constructed in Turkey until approximately 1960. After that, as reinforced concrete and masonry buildings have been preferred, wooden buildings have almost been forgotten. But, in 1999, Kocaeli and Duzce earthquakes reminded traditional buildings. Since reinforced concrete buildings presented high level of damage and traditional buildings relatively performed well during these earthquakes. In this study, types of traditional wooden buildings used in Turkey are mainly introduced and their damages in earthquakes are discussed. Damaged and undamaged wooden building photos are illustrated. Some structural weaknesses are highlighted by the earthquake damages including cracking and falling of plaster, failure of mortar, loosening or failing of connections, large lateral displacements, dislodgement of the masonry infill, loosening or failing of connections and failure of connections to foundation.
- MakaleYalnız künye2006Mineralogy, petrography and whole-rock geochemistry of the Tertiary granitic intrusions in the Eastern Pontides, Turkey
Arslan, M.; Aslan, Z.
Granitic intrusions in Eocene and post-Eocene volcanic rocks outcrop in the Northern and Southern Zones of the Eastern Pontides, NE Turkey. Intrusions in the Northern Zone extend NW-SE whereas those in the Southern Zone are nearly E-W orientated. The contacts of the intrusions with the volcanic rocks are sharp, epidotized and include volcanic xenoliths. The margins of Southern Zone intrusions often contain abundant angular mafic microgranular enclaves of diorite to quartz diorite composition. The rocks also show evidence of mingling and mixing between coeval mafic and felsic magmas. Field observations suggest a stopping type of ascent and emplacement style for the intrusions. Petrographically, intrusions show variations in both colour and mineralogy with fine to medium granular, monzonitic, poikilitic, rapakivi, anti-rapakivi and graphic textures. Based on modal mineralogy, the Northern rocks are monzonite, quartz monzonite, monzodiorite and quartz monzodiorite whereas the Southern samples are monzogranite and granodiorite. The rocks are generally calc-alkaline to mildly alkaline transitional and metaluminous, and show a CAFEMIC trend. The Northern Zone intrusions form a post-collisional, A-type, alkaline monzonitic association and Southern Zone intrusions form a post-collisional, I-type, granodioritic calc-alkaline-transitional association. Whole-rock compositional data indicate that differentiation occurred via fractional crystallisation with or without magma mixing. Incompatible and rare earth element patterns indicate that both the Northern and the Southern Zone intrusions were derived from melting of a mantle region enriched by subduction-related fluids but evolved differently during ascent and emplacement. U-Pb zircon dating in the Southern Zone yields an intrusion age of 44.4±0.3 Ma. Regional geodynamics indicates post-collisional extensional tectonics in the region. Crustal involvement and the level of emplacement may have been important for magmatic evolution, especially for the Southern Zone intrusions, after the cessation of subduction and subsequent crustal thickening.
- MakaleAçık Erişim2006A mantle- and a lower crust-derived bimodal suite in the Yusufeli (Artvin) area, NE Turkey: Trace element and REE evidence for subduction-related rift origin of Early Jurassic Demirkent intrusive complex
Dokuz, Abdurrahman; Tanyolu, Erkan; Genç, Salim
The Yusufeli area, in the Eastern Black Sea Region of Turkey, contains a crystalline complex that intruded into the Carboniferous metamorphic basement and is composed of two intrusive bodies: A gabbro-diorite and a tonalite-trondhjemite. The mafic body (45-57 wt% SiO2) displays a broad lithological spectrum ranging from plagioclase-cumulate to quartz diorite. Primitive varieties of the body have Mg-number, MgO and Cr contents that are close to those expected for partial melts from mantle peridotite. Data are consistent with the magma generation in an underlying mantle wedge that was depleted in Zr, Nb and Ti, and enriched in large ion lithophile elements (K, Rb, Ba, Th). However, high Al2O3, CaO and generally low Ni (<65 ppm) contents are not in agreement with the unfractionated mantle-derived primitive magmas and require some Al2O3- and CaO-poor mafic phases, in particular, olivine and orthopyroxene. Absence of orthopyroxene in crystallization sequence, uralitization, and a common appearance of clinopyroxene surrounded by hornblende imply an anhydrous phase fractionated from highly hydrous (5-6%) parent. Geochemical modelling suggests derivation by 15-20% melting of a depleted-lherzolitic mantle. The tonalite-trondhjemite body (58-76 wt% SiO2) ranges in composition from quartz diorite to granodiorite with a low-K calc-alkaline trend. Although LILE- and LREE- enriched characteristics of the primitive samples imply a metasomatic sub-arc mantle for their source region, low MgO, Ni and Cr concentrations rule out direct derivation from the mantle wedge. Also, lack of negative Eu anomalies suggests an unfractionated magma and precludes a differentiation from the diorites of mafic body, which show negative Eu anomalies. Their Na enrichments relative to Ca and K are similar to those of Archean tonalites, trondhjemites and granodiorites and Cenozoic adakites. However, they exhibit important geochemical differences from them, including low-Al (<15 wt%) contents, unfractionated HREE patterns and evolution towards the higher Y concentrations and lower Sr/Y ratios within the body. All these features are obtained in experimentally produced melts from mafic rocks at low pressures (≤5 kbar) and also widespread in the rocks of arc where old (Upper Cretaceous or older) oceanic crust is being subducted. Major and REE modelling supports formation of the quartz dioritic parent to the felsic intrusive rocks by 70% partial melting of a primitive gabbroic sample (G694). Therefore, once taking into account the extensional conditions prevailing in the Pontian arc crust in Early Jurassic time, former basic products (gabbros) seem to be the most appropriate source for the tonalite-trondhjemite body. Magmatic emplacement of stratigraphically similar lithologies in the Pulur Massif, just southwest of the Yusufeli, was dated to be 184 Ma by the 40Ar/ 39Ar method on amphibole, and is compatible with the initiation of Early Jurassic rifting in the region.
- MakaleYalnız künye2006Sedimentary records of the extensional tectonic regime with temporal cessation: Gümüşhane Mesozoic Basin (NE Turkey)
Yilmaz, Cemil; Kandemir, Raif
The Gümüşhane Mesozoic Basin is characterized by Lower-Middle Jurassic volcanic-siliciclastic sediments (Şenköy Formation), Upper Jurassic-Cenomanian platform carbonates (Berdiga Formation) and Upper Cretaceous turbidites (Kermutdere Formation). Four extensional periods (Lias-Dogger, Turonian-Coniacian, Late Campanian (?) and Early (?) Maastrichtian) separated by two quiet tectonic periods (early Malm-Cenomanian and Santonian-Campanian) have been defined in this sequence. The previous studies suggested that Mesozoic basins only formed by extensional movements in the middle Cretaceous. Three extensional periods seperated by two quiet periods from the Cenomanian to the end of the Maastrichtian in Gümüşhane and NE Turkey were firstly proved by sedimentological findings in this study. The definition of these periods depends on features such as (1) neptunian dykes in different levels, (2) shallow marine limestone, (3) thinning-and-fining-upward sequences, (4) mixed faunal assemblages, (5) micro-turbiditic structures, (6) syn-sedimentary fault, (7) grabens, half-grabens, (8) pelagic limestone, (9) calciturbidites, (10) laterally and vertically rapid changes of the thickness and facies, (11) platform-to-basin transition and (12) monogenic breccias.
- MakaleYalnız künye2006Simplified seismic analysis procedures for elevated tanks considering fluid-structure-soil interaction
Livaoǧlu, R.; Doǧangün, A.
This paper presents a review of simplified seismic design procedures for elevated tanks and the applicability of general-purpose structural analyses programs to fluid-structure-soil interaction problems for these kinds of tanks. Ten models are evaluated by using mechanical and finite-element modelling techniques. An added mass approach for the fluid-structure interaction, and the massless foundation and substructure approaches for the soil-structure interactions are presented. The applicability of these ten models for the seismic design of the elevated tanks with four different subsoil classes are emphasized and illustrated. Designers may use the models presented in this study without using any fluid and/or special soil elements. From the models defined here, single lumped-mass models underestimate the base shear and the overturning moment. Because almost all the other assumptions for the fixed base give similar results, any method could be used, but the distributed added mass with the sloshing mass is more appropriate than the lumped mass assumptions for finite-element modelling, and is recommended in this study.
- MakaleYalnız künye2006Three-directional extensional deformation and formation of the Liassic rift basins in the Eastern Pontides (NE Turkey)
Eyüboǧlu, Yener; Bektaş, Osman; Şeren, Aysel; Maden, Nafiz; Özer, Rahşan; Jacoby, Wolfgang R.
The Eastern Pontide magmatic arc (NE Turkey) was rifted by the polyphase extensional tectonic regimes in the Early Jurassic. While alternated volcanics and siliciclastic sedimentary rocks accumulated during the episodic tectonic subsidences, thermal subsidence is manifested by sedimentation of the red pelagic limestones of the Ammonitico Rosso during the Pliensbachian. The trends of the Liassic basins extending in NW-SE, E-W, NE-SW directions coincide with the gravity and magnetic lineament anomalies and corresponding fault zones that are responsible for the paleotectonic and neotectonic evolutions of the Eastern Pontide magmatic arc. These mutual relationships suggest that the faults making up the architecture of the Liassic basins might have operated during the Paleozoic, Mesozoic and Cenozoic times in different manners. Neptunian dikes, filled by the early rift siliciclastic and following fossiliferous red pelagic limestone implying the repeated extensional tectonic regimes, are also parallel to the main extensions of the Liassic basins. The poles of the contemporaneous neptunian dikes suggesting two or three extensional conjugate fracture systems are in accordance with the dip directions of the rift sediments accumulated in the same conjugate normal fault systems. Assuming that the Liassic basins with Ammonitico Rosso are coeval, multi-armed rift basins might have opened by the mode of the three-directional extension rather than reactivation of faults in the different times.
- MakaleYalnız künye2006Pre-eruptive conditions revealed by mega- and pheno-cryst compositions from the Quaternary Erzincan Volcanics, Eastern Turkey: Insights into the magma processes
Karsli, Orhan
Quaternary Erzincan Volcanics (QEVs) from the Erzincan Basin consist of mega- and pheno-cryst-bearing high-K calc-alkaline dome lavas. Fourteen nearly phenocrystic domes, with a range of basaltic-andesite, andesite, dacite and rhyolite compositions, were emplaced in the North Anatolian Fault Zone. The emplacement ages yielded by the unspiked K-Ar technique range from 102 to 140 ka. The andesitic domes (each less than 3 km in diameter) contain amphibole megacrysts. Amphibole compositions show a linear variation from ferro-edenite, edenite to pargasite from rhyolite to andesite. Pargasitic amphibole megacrysts scattered into the groundmass are very similar in composition to the microlites. All plagioclases are <An53 mol%. Oscillation types are An32-50 whose variations range from 10 to 16 mol% An and have 10-150 μm in thickness. Pre-eruptive conditions, calculated from mega- and pheno-cryst composition, using pyroxene and two oxide thermometers and the Al-in-hornblende barometer, ranged from 918 to 837 °C and 6.6 to 4.3 kbar for andesitic magma, 824-755 °C and 4.6-4.2 kbar for dacitic magma to 803-692 °C and 4.3-3.9 kbar for rhyolitic magma, which correspond to a depth of >10 km for storage region of the crust. The fO2 values vary from -14.25 to -15.35 log units which are plotted just below nickel-nickel oxide (NNO) buffers. The systematic decrease in thermobarometric results from andesite to rhyolite is consistent with a single magma reservoir moving upward through the crust followed by fractional crystallization. Textural and compositional relationships of mega- and pheno-crystic phases suggest that magma mixing, fluid input to the reservoir and fractional crystallization processes, with a small amount crustal contamination play key role in evolution of the QEVs.
- BildiriYalnız künye2006Is postprandial 2h glucose level a real determinant for glucose intolerance in people at risk for type 2 diabetes? RISK study results - I
Yilmaz, T.; Sargin, M.; Olmez, B.; Karadeniz, S.; Oguzhan, B.