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2001

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Articles 2671 - 2700 of 3030

Full-Text Articles in Physical Sciences and Mathematics

The Theoretical Analysis Of The Second Order Coherence G^{(2)}(\Tau) And Power Stabilization Of Two-Mode He-Ne Laser, Erol Taşal, M. Selami̇ Kiliçkaya Jan 2001

The Theoretical Analysis Of The Second Order Coherence G^{(2)}(\Tau) And Power Stabilization Of Two-Mode He-Ne Laser, Erol Taşal, M. Selami̇ Kiliçkaya

Turkish Journal of Physics

In this study, second-order coherence and its frequency-dependent characteristics and the photon statistical properties of the two-mode He-Ne laser field are investigated.


Effect Of Nitriding On Phase Transformations In The Fe-Mn Alloys, K. G. Binnatov, I. I. Ali-Zade, A. O. Mekhrabov Jan 2001

Effect Of Nitriding On Phase Transformations In The Fe-Mn Alloys, K. G. Binnatov, I. I. Ali-Zade, A. O. Mekhrabov

Turkish Journal of Physics

We present results concerning the nitriding effects on phase transformations in Fe -- 40 at. % Mn and Fe -- 50 at. % Mn alloys. These alloys were studied by means of X-ray diffraction and Mössbauer-effect spectroscopy methods at room temperature. Results indicate that, after nitriding, in the absorption spectra of these alloys appears lines with hyperfine field H\sim 330 kOe which corresponds to the field on the ^{57} Fe nuclei in the \alpha -Fe. Annealing of the alloys at 650 ^oC temperature (nitriding temperature) in argon atmosphere do not change the form of the M\\"{o}ssbauer absorption spectra. It appears …


Spatial Assessment Of Nonpoint Phosphorus Sources Using Streambed Sediment Monitoring In The Kings River Basin, Nw Arkansas, Jason W. White Jan 2001

Spatial Assessment Of Nonpoint Phosphorus Sources Using Streambed Sediment Monitoring In The Kings River Basin, Nw Arkansas, Jason W. White

MSU Graduate Theses

This study of the Kings River Basin provides a watershed-scale assessment of streambed sediment-Phosphorus (P) and its sources on the landscape. The Kings River drains into Table Rock Lake where surface algal blooms have concerned water scientists and disrupted summer tourism. There are questions about how sediment loads, widespread poultry and cattle operations, and sewage treatment plants are affecting water quality. Previous water quality studies across the U.S. have generally evaluated watercolurnn P. In contrast, few studies have used streambed sediment monitoring to detect P levels at a watershed-scale, and none have been attempted in the Kings River Basin. Sediment …


Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu Jan 2001

Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu

Turkish Journal of Physics

Influence of above-molecular structure (AMS) on electrothermoluminescence, the altering time and the mechanic time of polymer dielectrics in strong electric fields that depend on temperature have been investigated. It has been shown that change of AMS considerably influenced the processes of injection and stabilization of charges as well as the solidity properties of polymers. It has been determined that the relaxation translations in large spherolite samples were observed at lower temperatures than the relaxation translations in small spherolite samples.


Beta Spectrometers With Surface Barrier Detector And Plastic Scintillator: Applications To ^{90}Sr,^{204}Tl,^{210}Pb And ^{14}C, Cüneyt Çeli̇ktaş Jan 2001

Beta Spectrometers With Surface Barrier Detector And Plastic Scintillator: Applications To ^{90}Sr,^{204}Tl,^{210}Pb And ^{14}C, Cüneyt Çeli̇ktaş

Turkish Journal of Physics

In this work, a comparison of responses between a spectrometer using Si Surface Barrier Detector (Si SBD) and a spectrometer using Plastic Scintillator (PS) is given. Experimental pulse height spectra of beta particles from ^{90}Sr,^{204}Tl,^{210}Pb and ^{14}C pure beta sources has been obtained separately. By comparing obtained spectra, the priority of obtaining the beta spectra among them is discussed. This work is related to the spectral response of beta spectrometers to pure beta sources.


Mössbauer-Effect Study Of Fine Atomic Structure Of Fe-Ni-C Alloys, K. G. Binnatov, A. O. Mekhrabov Jan 2001

Mössbauer-Effect Study Of Fine Atomic Structure Of Fe-Ni-C Alloys, K. G. Binnatov, A. O. Mekhrabov

Turkish Journal of Physics

Fine atomic structure of Fe-Ni-C alloys containing of 30-36 wt. % Ni and 0.1-1.0 wt. % C have been analysed by means of a nuclear \gamma -resonance method. The alloys under investigation were in austenite phase. The study shows that the effective hyperfine magnetic field H_{eff} on the ^{57}Fe nuclei is affected by the presence of C atoms in Fe-Ni alloys and the mean value of H_{eff} fields increase with increasing of C element content in these alloys. It has been detected that increase in carbon content in Fe-Ni alloys leads to a broadening of Mössbauer absorption lines. On the …


Factors Affecting Radon Concentration In Houses, Abdel-Latif Al-Sharif, Y. S. Abdelrahman Jan 2001

Factors Affecting Radon Concentration In Houses, Abdel-Latif Al-Sharif, Y. S. Abdelrahman

Turkish Journal of Physics

The dangers to the human health upon exposure to radon and its daughter products is the main motivation behind the vast number of studies performed to find the concentration of radon in our living environment, including our houses. The presence of radon and its daughter products in houses are due to various sources including building materials and the soil under the houses. Many factors affect radon concentration in our houses, the elevation above ground level,ventilation, building materials and room usage being among these factors. In our paper, we discuss the effect of elevation above ground level, room usage and ventilation …


A Facile And Efficient Method For The Rearrangement Of Aryl-Substituted Epoxides To Aldehydes And Ketones Using Bismuth Triflate, Ram Mohan, Kaushik Bhatia, Kyle Eash, Nicholas Leonard, Matthew Oswald Jan 2001

A Facile And Efficient Method For The Rearrangement Of Aryl-Substituted Epoxides To Aldehydes And Ketones Using Bismuth Triflate, Ram Mohan, Kaushik Bhatia, Kyle Eash, Nicholas Leonard, Matthew Oswald

Scholarship

Aryl-substituted epoxides undergo smooth rearrangement in the presence of 0.01–0.1 mol% Bi(OTf)3•xH2O. The rearrangement is regioselective with aryl-substituted epoxides, and products arise from cleavage of the benzylic C―O bond. The highly catalytic nature of this method coupled with the fact that the reagent is relatively non-toxic, easy to handle and inexpensive make it an attractive alternative to more corrosive and toxic Lewis acids, such as BF3•Et2O, currently used to effect epoxide rearrangements.


The Discovery-Oriented Approach To Organic Chemistry. 5. Stereochemistry Of E2 Elimination: Elimination Of Cis- And Trans-2-Methylcyclohexyl Tosylate, Ram Mohan, Marcus Cabay, Brad Ettlie, Adam Tuite, Kurt Welday Jan 2001

The Discovery-Oriented Approach To Organic Chemistry. 5. Stereochemistry Of E2 Elimination: Elimination Of Cis- And Trans-2-Methylcyclohexyl Tosylate, Ram Mohan, Marcus Cabay, Brad Ettlie, Adam Tuite, Kurt Welday

Scholarship

The E2 elimination is one of the most important reactions in organic chemistry and is discussed in considerable detail in a sophomore organic course. We have developed a discovery-oriented lab that illustrates the stereochemistry of the E2 elimination reaction and is a good exercise in 1H NMR spectroscopy. The added element of discovery insures that student interest and enthusiasm are retained.


An Efficient Method For The Chemoselective Synthesis Of Acylals From Aromatic Aldehydes Using Bismuth Triflate, Ram Mohan, Marc Carrigan, Kyle Eash, Matthew Oswald Jan 2001

An Efficient Method For The Chemoselective Synthesis Of Acylals From Aromatic Aldehydes Using Bismuth Triflate, Ram Mohan, Marc Carrigan, Kyle Eash, Matthew Oswald

Scholarship

Aromatic aldehydes are smoothly converted into the corresponding acylals in good yields in the presence of 0.10 mol% Bi(OTf)3•xH2O. Ketones are not affected under the reaction conditions. The highly catalytic nature of bismuth triflate and the fact that it is relatively non-toxic, easy to handle and insensitive to small amounts of air and moisture makes this procedure especially attractive for large-scale synthesis.


The Discovery-Oriented Approach To Organic Chemistry. 4. Epoxidation Of P-Methoxy-Trans-Β-Methylstyrene. An Exercise In 1H Nmr And 13C Nmr Spectroscopy For Sophomore Organic Laboratories, Ram Mohan, Rebecca Centko Jan 2001

The Discovery-Oriented Approach To Organic Chemistry. 4. Epoxidation Of P-Methoxy-Trans-Β-Methylstyrene. An Exercise In 1H Nmr And 13C Nmr Spectroscopy For Sophomore Organic Laboratories, Ram Mohan, Rebecca Centko

Scholarship

Epoxidation of alkenes using peroxyacids is one of the most fundamental reactions in organic chemistry, yet there are very few examples of laboratory experiments that illustrate this important reaction. We have developed a discovery-oriented lab experiment that illustrates epoxidation of alkenes as well as the reactivity of epoxides toward acids. The experiment involves reaction of p-methoxy-trans-β-methylstyrene (trans-anethole) with m-chloroperoxybenzoic acid (MCPBA), in both the absence and presence of a buffer, followed by product identification using 1H NMR, 13C NMR, and IR spectroscopy. The added element of discovery ensures that students' interest and enthusiasm are retained.


Deprotection Of Ketoximes Using Bismuth(Iii) Nitrate Pentahydrate, Ram Mohan, Bryce Nattier, Kyle Eash Jan 2001

Deprotection Of Ketoximes Using Bismuth(Iii) Nitrate Pentahydrate, Ram Mohan, Bryce Nattier, Kyle Eash

Scholarship

Ketoximes undergo facile deprotection in acetone-H20 (9: 1) in the presence 01' 0.5 equivalents of Bi(N03h•5H20. Bismuth(III) nitrate is relatively non-toxic, insensitive to air and inexpensive. These features coupled with the use of a relatively nontoxic solvent system make this method an attractive alternative to existing routes for deprotection of ketoximes.


Controlling The Optical Properties Of A Conjugated Co-Polymer Through Variation Of Backbone Isomerism And The Introduction Of Carbon Nanotubes, A. Dalton, J. Coleman, M. In Het Panhuis, B. Mccarthy, A. Drury, W. Blau, J. Nunzi, Hugh Byrne Jan 2001

Controlling The Optical Properties Of A Conjugated Co-Polymer Through Variation Of Backbone Isomerism And The Introduction Of Carbon Nanotubes, A. Dalton, J. Coleman, M. In Het Panhuis, B. Mccarthy, A. Drury, W. Blau, J. Nunzi, Hugh Byrne

Articles

The need to control the formation of weakly emitting species in polymers such as aggregates and excimers, which are normally detrimental to device performance, is illustrated for the example of the polymer poly(m-phenylenevinylene-co-2,5-dioctyloxy-p-phenylenevinylene), using the model compound, 2,5-dioctyloxy-p-distyrylbenzene as a comparison. Two different methods, namely a Homer-Emmons polycondensation in dimethylformamide (DMF) and a Wittig polycondensation in dry toluene, have been used during synthesis resulting in a polymer with a predominantly trans-vinylene backbone and a polymer with a predominantly cis-vinylene backbone, respectively. Photoluminescence and absorption spectroscopy indicate that the polymer forms aggregate species in solution with spectra that are distinctly red-shifted …


Effective Field Theory For The Small-X Evolution, I. Balitsky Jan 2001

Effective Field Theory For The Small-X Evolution, I. Balitsky

Physics Faculty Publications

The small-x behavior of structure functions in the saturation region is determined by the non-linear generalization of the BFKL equation. I suggest the effective field theory for the small-x evolution which solves formally this equation. The result is the 2+1 functional integral for the structure functions at small x.


Electron Heating In Atmospheric Pressure Glow Discharges, Robert H. Stark, Karl H. Schoenbach Jan 2001

Electron Heating In Atmospheric Pressure Glow Discharges, Robert H. Stark, Karl H. Schoenbach

Bioelectrics Publications

The application of nanosecond voltage pulses to weakly ionized atmospheric pressure plasmas allows heating the electrons without considerably increasing the gas temperature, provided that the duration of the pulses is less than the critical time for the development of glow-to-arc transitions. The shift in the electron energy distribution towards higher energies causes a temporary increase in the ionization rate, and consequently a strong rise in electron density. This increase in electron density is reflected in an increased decay time of the plasma after the pulse application. Experiments in atmospheric pressure air glow discharges with gas temperatures of approximately 2000 K …


Resonant Energy Transfer From Argon Dimers To Atomic Oxygen In Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz Jan 2001

Resonant Energy Transfer From Argon Dimers To Atomic Oxygen In Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz

Bioelectrics Publications

The emission of atomic oxygen lines at 130.2 and 130.5 nm from a microhollow cathode discharge in argon with oxygen added indicates resonant energy transfer from argon dimers to oxygen atoms. The internal efficiency of the vacuum-ultraviolet (VUV) radiation was measured as 0.7% for a discharge in 1100 Torr argon with 0.1% oxygen added. The direct current VUV point source operates at voltages below 300 V and at current levels of milliamperes.


Xenon Excimer Emission From Pulsed Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz Jan 2001

Xenon Excimer Emission From Pulsed Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz

Bioelectrics Publications

By applying electrical pulses of 20 ns duration to xenon microplasmas, generated by direct current microhollow cathode discharges, we were able to increase the xenon excimer emission by more than an order of magnitude over direct current discharge excimer emission. For pulsed voltages in excess of 500 V, the optical power at 172 nm was found to increase exponentially with voltage. Largest values obtained were 2.75 W of vacuum-ultraviolet optical power emitted from a single microhollow cathode discharge in 400 Torr xenon with a 750 V pulse applied to a discharge. Highest radiative emittance was 15.2 W/cm2. The …


Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant Jan 2001

Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant

Conference papers and presentations

Seagrass, which once dominated the habitat of Oyster Harbour on the south coast of Western Australia has been replaced by macroalgae because of increased nutrient and sediment discharge from the rural dominated catchment. Total Phosphorus (TP), Total Nitrogen (TN), Suspended Sediment (SS) and Electrical Conductivity (EC) concentrations from a catchment – wide (168 sites), event-driven snapshot, water quality monitoring program conducted from 1994 to 1996, were analysed in relation to stream order and published survey data on riparian zone condition. This analysis was performed to examine relationships between stream order, riparian zone condition and water quality, and implications for the …


Development Of A Basic Gis Database For The Yeşilırmak Watershed Provinces Using Satellite Images And Other Data, Hülya Yildirim, Erhan Alparslan, Mehmet Emi̇n Özel, Ci̇hangi̇r Aydöner, Samuray Eli̇taş, Nalan Jale Di̇van, Mehmet Dağci, Asli Süha Dönertaş Jan 2001

Development Of A Basic Gis Database For The Yeşilırmak Watershed Provinces Using Satellite Images And Other Data, Hülya Yildirim, Erhan Alparslan, Mehmet Emi̇n Özel, Ci̇hangi̇r Aydöner, Samuray Eli̇taş, Nalan Jale Di̇van, Mehmet Dağci, Asli Süha Dönertaş

Turkish Journal of Earth Sciences

Remote-sensing and geographic-information-systems (GIS) techniques were jointly used in this study to establish a GIS database system for the Yeşilırmak watershed provinces, which include Amasya, Tokat, Çorum, Yozgat and Samsun. Composite multicolour images (down to 6 m resolution) from the LANDSAT TM and Indian IRS C/D satellites, land-use/land-cover maps derived from these images, road networks, soil information, digital terrain model, slope and aspect information derived from digital elevation data and meteorological data at province level are the major constituents of this database. A 'project office' has been established with trained personnel at each province centre to effectively use the resultant …


Post-Collisional Magmatism On The Northern Margin Of The Taurides And Its Geological Implications: Geology And Petrology Of The Yahyalı-Karamadazı Granitoid, Gonca Gençali̇oğlu Kuşcu, M. Cemal Göncüoğlu, İlkay Kuşcu Jan 2001

Post-Collisional Magmatism On The Northern Margin Of The Taurides And Its Geological Implications: Geology And Petrology Of The Yahyalı-Karamadazı Granitoid, Gonca Gençali̇oğlu Kuşcu, M. Cemal Göncüoğlu, İlkay Kuşcu

Turkish Journal of Earth Sciences

The Karamadazı Granitoid (Yahyalı-Kayseri) is a typical example of bimodal magmatism on the northern margin of the Eastern Tauride belt. The Karamadazı Granitoid intrudes the Palaeozoic-Mesozoic Yahyalı metamorphic rocks and is unconformably overlain by Upper Maastrichtian clastics. It consists of granodiorite-quartz diorite as the main intrusive phase, and includes leucogranites and aplitic dykes in its marginal parts. Samples from the Karamadazı Granitoid are calc-alkaline and calcic in character. The granodiorites are mainly metaluminous, whereas leucogranites and aplites are weakly peraluminous in nature. Plots of major-element oxides against SiO2 indicate a poor fractionation trend for the granodiorites. The leucogranites represent highly …


Metamorphic And Tectonic Evolution Of The Hırkadağ Block, Central Anatolian Crystalline Complex, Donna L. Whitney, Yildirim Di̇lek Jan 2001

Metamorphic And Tectonic Evolution Of The Hırkadağ Block, Central Anatolian Crystalline Complex, Donna L. Whitney, Yildirim Di̇lek

Turkish Journal of Earth Sciences

The Hırkadağ metamorphic block is a NE-SW-trending horst structure that is part of the Kırşehir Massif in the Central Anatolian Crystalline Complex (CACC). Along its southwestern margin, the block contains upper amphibolite facies metapelitic rocks that record peak metamorphic conditions of 670-710 °C, ~ 7 kbar, as determined by garnet-biotite geothermometry and garnet-sillimanite-plagioclase-quartz, garnet-rutile-sillimanite-ilmenite-quartz, and garnet-rutile-ilmenite-plagioclase-quartz geobarometry. A clockwise pressure-temperature path is inferred from thermobarometric results and analysis of reaction textures among aluminous phases. Following this medium-pressure metamorphism, low-pressure - high-temperature metamorphism resulted in widespread replacement of garnet by cordierite + spinel + sillimanite, partial replacement of spinel by corundum, …


Repetitive Subtidal-To-Coastal Sabkha Cycles From A Lower-Middle Miocene Marine Sequence, Eastern Sivas Basin, Faruk Ocakoğlu Jan 2001

Repetitive Subtidal-To-Coastal Sabkha Cycles From A Lower-Middle Miocene Marine Sequence, Eastern Sivas Basin, Faruk Ocakoğlu

Turkish Journal of Earth Sciences

In the study area, southeast of Zara in the Sivas Basin, the Lower-Middle Miocene marine Karacaören Formation consists of a succession of marine sedimentary rocks deposited within two trangressive-regressive cycles. The present study focuses on the facies characteristics, cyclic nature, and significance of the basin-wide distribution of a 100-m-thick gypsiferous sedimentary package overlying an otherwise transgressive segment of the lower sequence, within a marine setting. The typical lithologic expression of the studied sedimentary interval comprises generally fossiliferous mudstones, rare algal limestones and nodular gypsum. Detailed sedimentological observations, combined with palaeontological evidence, indicate that the mudstone intervals were deposited in a …


Stratigraphy, Geochemistry And Depositional Environment Of The Celestine-Bearing Gypsiferous Formations Of The Tertiary Ulaş-Sivas Basin, East-Central Anatolia (Turkey), Erdoğan Teki̇n Jan 2001

Stratigraphy, Geochemistry And Depositional Environment Of The Celestine-Bearing Gypsiferous Formations Of The Tertiary Ulaş-Sivas Basin, East-Central Anatolia (Turkey), Erdoğan Teki̇n

Turkish Journal of Earth Sciences

Celestine-bearing evaporite mineralization is widespread in the Tertiary evaporitic units of the Ulaş-Sivas Basin, east-central Anatolia. The oldest deposition of gypsum, which is of laminated character, occurred in a shallow inner-lagoonal environment or in depressions during Late Eocene regression. Thick gypsum and overlying beds composed of alternating bedded, nodular gypsum and sandstone developed in coastal sabkhas and abandoned channels within a meander-river complex during Oligocene time. The last occurrence of evaporitic units, namely massive and bedded gypsum alternating with sandstones and fossiliferous limestones, resulted from limited marine transgression of an Early Miocene sea along the southern margin of the Sivas …


The June 6, 2000, Orta (Çankırı, Turkey) Earthquake: Sourced From A New Antithetic Sinistral Strike-Slip Structure Of The North Anatolian Fault System, The Dodurga Fault Zone, Ali̇ Koçyi̇ği̇t, Bora Rojay, Mustafa Ci̇han, Arda Özacar Jan 2001

The June 6, 2000, Orta (Çankırı, Turkey) Earthquake: Sourced From A New Antithetic Sinistral Strike-Slip Structure Of The North Anatolian Fault System, The Dodurga Fault Zone, Ali̇ Koçyi̇ği̇t, Bora Rojay, Mustafa Ci̇han, Arda Özacar

Turkish Journal of Earth Sciences

The İsmetpaşa-Kargı section of the North Anatolian Fault System (NAFS) consists of six subfault zones, namely the Eskipazar, the Ulusu, the Tosya, the Çerkeş-Kurşunlu, the Devrez and the newly detected Dodurga fault zone (DFZ). Together these fault zones form a well-developed dextral strike-slip-faulting pattern, in which the DFZ is an antithetic secondary strike-slip component, indicated by focal-mechanism solutions of moderate and large earthquakes that have occurred in the İsmetpaşa-Kargı section of the NAFS. The DFZ is a ~36-km-long, ~N-S-trending strike-slip structure located in the area between Saçak village in the north and Kösrelik village in the south. Pre-Upper Pliocene rocks …


Characteristics Of The Weathering Zones Developed Within The Tuffs Of The Midas Monument, Tamer Topal, Burak Sözmen Jan 2001

Characteristics Of The Weathering Zones Developed Within The Tuffs Of The Midas Monument, Tamer Topal, Burak Sözmen

Turkish Journal of Earth Sciences

The Midas monument, an impressive cult facade located in the southern part of the Eskişehir province in central Anatolia, Turkey, was made within tuffs (white and pink), which now have deterioration problems. In this study, the depth and characteristics of the weathering zones that have developed in the white and pink tuffs have been investigated through thin-section studies, X-ray powder diffractometry, methylene blue adsorption tests, major-element analyses, and some index parameters. It has been determined that the feldspar minerals are mechanically fractured due to weathering. The tuffs contain small amounts of clay minerals. An approximately 1-cm-thick silica-rich zone has developed …


Tectonic Implications Of Some Cretaceous Pillow Basalts From The North Anatolian Ophiolitic Mélange(Central Anatolia-Turkey) To The Evolution Of Neotethys, Bora Rojay, Kenan M. Yaliniz, Demi̇r Altiner Jan 2001

Tectonic Implications Of Some Cretaceous Pillow Basalts From The North Anatolian Ophiolitic Mélange(Central Anatolia-Turkey) To The Evolution Of Neotethys, Bora Rojay, Kenan M. Yaliniz, Demi̇r Altiner

Turkish Journal of Earth Sciences

The most widespread blocks within the North Anatolian ophiolitic mélange of central Anatolia (Turkey) are ophiolitic fragments, Jurassic-Cretaceous carbonate blocks and pillow basalts. The blocks of pillow basalts have an immobile trace-element geochemistry that is characteristic of ocean-island alkali basalts. An N-MORB-normalized spider diagram shows a distinctive enrichment of most incompatible trace elements and exhibits a far greater range of absolute abundances than N-MORB. Selected incompatible-element contents and ratios of basalts show high Ba/Nb (~8),low Zr/Nb(~5)and low La/Nb(~0.5)relative to N-MORB. The presence of thin-shelled \"Protoglobigerina\" and Cadosina associated with miliolids and epistominid foraminifers indicates that the age of the pink …


Geochemistry And Mineralogy Of The Skarns In The Çelebi District, Kırıkkale, Turkey, İlkay Kuşcu Jan 2001

Geochemistry And Mineralogy Of The Skarns In The Çelebi District, Kırıkkale, Turkey, İlkay Kuşcu

Turkish Journal of Earth Sciences

The Çelebi district is well known for its polymetallic Fe-W and Cu vein ores. These ores are hosted by calcic skarn zones, which are broadly classified as \"intrusive around skarn\" type. Both exoskarns (pyroxene-garnet) and endoskarns (epidote-pyroxene) occur in the district. The formation of endoskarns is manifested by complete replacement of plagioclase by epidote and pyroxene; the epidotized granitoids are regarded as incipient and/or early metasomatic products. The abundance of pyroxene in endoskarns tends to increase with plagioclase content and within the groundmass of the granitoids towards exoskarn zones. The increase in pyroxene is also coincident with the formation of …


A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk Jan 2001

A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk

Turkish Journal of Earth Sciences

As a result of recent disasters in northwest Turkey (Marmara earthquake August 17, 1999/Düzce earthquake November 12, 1999), many buildings collapsed and many people experienced physical and mental problems. We can suppose that the problems caused by these earthquakes will be solved in the future, but geological studies show that the problems will not disappear in that many scientists are predicting a new disaster that will affect the same region. A design of natural-hazard land-use planning for minimising the consequences of recent and possible earthquakes is presented herein. The Adapazarı case is used to demonstrate the fundamentals of this study. …


Obituary, Aral İ. Okay, M. Cemal Göncüoğlu Jan 2001

Obituary, Aral İ. Okay, M. Cemal Göncüoğlu

Turkish Journal of Earth Sciences

No abstract provided.


Relationship Between Durophagy And Feeding Biomechanics In Gray Triggerfish, Balistes Capriscus: Intraspecific Variation In Ecological Morphology, Christopher J. Durie, Ralph G. Turingan Jan 2001

Relationship Between Durophagy And Feeding Biomechanics In Gray Triggerfish, Balistes Capriscus: Intraspecific Variation In Ecological Morphology, Christopher J. Durie, Ralph G. Turingan

Ocean Engineering and Marine Sciences Faculty Publications

The relationship between oral jaw biomechanics and consumption of hard prey was compared between Gulf of Mexico (Gulf) and Atlantic Ocean (Atlantic) populations of gray triggerfish (Balistes capriscus) to examine intraspecific ecomorphological variation between these fish. Gut content analysis revealed that Atlantic fish fed more on hard-shelled invertebrates, such as crabs and sea urchins, than Gulf conspecifics. Difference in the relative magnitude of durophagy between Gulf and Atlantic triggerfish was associated with intraspecific differences in key biomechanical properties of the prey-capture and processing mechanism. The more durophagous Atlantic B. capriscus had more massive jaw bones and muscles than Gulf fish. …