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Synthesis and biological evaluation of 3'-N-thiocarbamate paclitaxel derivatives
Get PDFPaklitaksel (Taxol®), porsuk ağacı (Taxus Brevifolia) kabuğundan izole edilen doğal bir diterpen alkaloididir. Paklitaksel,mikrotübül polimerine bağlanarak depolimerizasyona karşı kararlılığın sağlanmasında rol oynar. Günümüzde göğüs ve rahim kanserlerinin kemoterapisinde kullanılan en önemli ilaçlardan biridir.Paklitaksel üzerine yapılan araştırmalardaki amaçlardan biri de yapısal olarak daha basit ancak klinik olarak daha etkili analogların sentezlenmesidir. Sentezlenen paklitaksel analoglarının büyük bir kısmı 3'-N pozisyonunun türevlendirilmesiyle elde edilmiştir.Bu çalışmada yan zincirinde tiyokarbamat ve 2-tiyenil içeren yeni paklitaksel türevlerinin sentezi gerçekleştirilmiştir. Sentezlenen bu paklitaksel türevlerinin A2780 memeli yumurta hücrelerindeki aktiviteleri ölçülmüştür. Yapılan aktivite testlerinde bazı bileşiklerin Taxol ile kıyaslanabilen aktivite değerlerine sahip olduğu görülmüştür. Anahtar Kelimeler: Paklitaksel, tübülin, tiyokarbamat.Paclitaxel (Taxol®) is a natural occurring diterpene alkoloid originally isolated from the bark of Taxus Brevifolia. It is now one of the most important chemotherapeutic agents for clinical treatment of ovarian and breast cancer for the past decades. Recent clinical trials have also shown paclitaxel's potential for the treatment of non-small-cell lung cancer, head and neck cancer, and other types of cancers. While tremendous chemical research efforts have been made in the past years, which established the fundamental structure-activity relationships of the paclitaxel molecule, and have provided analogs for biochemical studies to elucidate the precise mechanism of action for the devolopment of second-generation agents, many areas remain to be explored. One of the principal goals associated with research is the identification of the structural features of Ttaxol required for its biochemical and physiological performance. Ultimately, such research can be expected to lead to the identification of structurally simpler and clinically more effective analogues. A large number of analogues prepared by others have incorporated modifications at the side chain 3´-N position, and some compounds with such modifications are in clinical trials. In a continuation of the studies on the structure/activity relationships of paclitaxel analogues, we now report the synthesis of novel sulfur containing paclitaxel side-chain analogues. Keywords: Paclitaxel, tubulin, thiocarbamate
Characteristics of the copper vapor thermionic vacuum arc discharge
Get PDFSaf metal buharlarında bir deşarjın oluşturulması ve çalışılması, metal atomlarının uygun buhar basıncını elde etmek için gerekli sıcaklığın yüksek olması nedeniyle zor bir problemdir. Termiyonik vakum ark (TVA) deşarj, doğrudan ısıtılan termiyonik katotlar kullanarak anotun buharlaşmasıyla oluşan yeni tip bir deşarjdır. Saf metal buharlarındaki bu deşarj, herhangi tür metal buharlarında ve ayrıca erimeyen metallerin buharlarında da oluşturulabilmektedir. TVA deşarj, yönlendirilmiş enerjili iyonlar içeren saf, gaz karışımı bulunmayan metal buharı plazması üretmektedir. TVA deşarjların gözlenen akım voltaj karakteristikleri, termiyonik katotun sıcaklığına, buharlaştırılan anot materyalinin cinsine ve elektrotların birbirine göre konumuna bağlıdır. Anahtar Kelimeler: Bakır, metal buharları, termiyonik katot, vakum ark deşarj.The production and study of a discharge in pure metal vapors is a diffucult problem due to the high temperature needed to obtain a convenient vapor pressure of the metal atoms. The thermionic vacuum arc(TVA) discharge is a new type of discharge with evaporating anodes employing directly heated thermionic cathodes. This discharge in pure metal vapors can be ignited in any kind of metal vapors including refractory metals too. The TVA discharge generates a pure, gas-free metal vapor plasma containing ions with a directed energy. The discharge is produced in vacuum between a heated cathode and an anode. The electrons emitted from the cathode are accelerated toward the anode by the applied voltage accross the electrodes, the flux of electrons being concentrated on a small area of the anode surface which becomes a melted metal spot. At a further increase of the applied voltage, an intense discharge is established in the metal vapors, evaporated from the anode. Because of the high power density incident on the anode surface, especially after arc ignition, high evaporation rate of the anode material is observed. The observed volt-ampere characteristics of the TVA discharges depend strongly on the temperature of the thermionic cathode, the evaporated anode material and the relative position of the electrodes. Keywords: Copper, metal vapors, thermionic cathode, vacuum arc discharge
Preparation of fast responsive macroporous hydrogels from frozen solutions
Get PDFBu çalışmada, 2-akrilamido-2-metilpropan sülfonik asit sodyum tuzu’nun (AMPS) sulu ortamlarda N,N-metilenbisakrilamid (BAAm) çapraz bağlayıcısı ile kopolimerizasyonu incelenmiştir. AMPS monomeri ile BAAm çapraz bağlayıcısının sulu çözeltileri başlatıcı amonyum persülfat (APS) ile hızlandırıcı N,N,N’,N’-tetraetilmetilendiamin (TEMED) redoks başlatıcı sistemi ile polimerizasyon sisteminin donma noktasının altında ve üzerinde gerçekleştirilmiştir. Elde edilen hidrojellerin şişmiş durumdaki elastik modülleri, sudaki şişme oranları, aseton ve sudaki büzülme ve şişme hızları ölçülmüştür. Taramalı elektron mikroskobu yardımı ile polimer ağyapılarının morfolojileri incelenmiştir. Hidrojellerin şişme ve elastik özelliklerinin -8ºC gibi bir jel hazırlama sıcaklığında belirgin bir şekilde değiştiği gözlenmiştir. -8ºC’nin altında sentezlenen hidrojelleri oluşturan ağyapıların gözenekli olduğu ve gözenek çaplarının 30-50 mm arasında değiştiği buna karşılık -8ºC ve üzerinde sentezlenen ağyapıların gözenek içermediği görülmüştür. Hazırlanan Poli(AMPS)(PAMPS) hidrojellerinin mikroyapısının, karnıbahara benzeyen ve değişik büyüklüklerde agregatlar içeren, reaksiyona bağlı faz ayrılma mekanizmasıyla oluşan makrogözenekli ağyapılardan belirgin bir şekilde farklı oldukları ortaya çıkarılmıştır. Bununla birlikte, -8ºC’nin altında sentezlenen PAMPS hidrojelleri için, suda ve asetonda tamamen tersinir şişme-büzülme eğrileri elde edilmiştir. -8ºC’nin altında oluşan jeller, denge şişme hacimlerine 30 saniyede ulaşırken, yüksek sıcaklıklarda oluşan jellerin suda denge durumlarına ulaşmaları için 1 saat gerekmiştir. Ayrıca, şişmiş PAMPS jelleri asetona daldırıldığında, -8ºC’nin altında hazırlanan jeller 5 ile 10 dakika arasında büzülerek dengeye ulaşırken, yüksek sıcaklıklarda sentezlenenler ise hacim değişimlerine dayanamayarak parçalanmıştır. Böylelikle, jel hazırlama sıcaklığının -8ºC’nin altına indirilmesi ile hacim değişimlerine karşı dayanıklı süper hızlı şişen PAMPS hidrojelleri elde edilmiştir. Anahtar Kelimeler: Hidrojel, şişme, donma, makrogözenek. Responsive hydrogels are smart materials, capable of changing volume in response to specific external stimuli, such as the temperature, solvent quality, pH, electric field, etc. These properties of hydrogels received considerable interest in last three decades and, a large number of hydrogel based devices have been proposed, including artificial organs, actuators, and on-off switches. Important parameters of hydrogels, which to a large extent determine their performance, are an improved mechanical property as well as a fast swelling-deswelling rate to the external stimuli. However, in some applications, such as artificial organs, the conventional hydrogel with slow response rate cannot satisfy this requirement. Therefore, the slow response rate of the hydrogels limits their technological applications. Increasing the response rate of hydrogels has been one of the challenging problems in the last 25 years. In this regard, several strategies have been proposed. A widely used approach to obtain fast responsive hydrogels is to create voids (pores) inside the hydrogel matrix, so that the response rate becomes a function of the microstructure rather than the size or the shape of the gel samples. A new and contradictory method to produce macroporous hydrogels and thus, increasing their response rate is conducting the polymerization reactions below the freezing point of the reaction system. This low temperature gelation so-called cryogelation was used to create an interconnected pore structure within the polymer networks. In this cryogelation process, the reaction system is partially frozen after the onset of polymerization reaction. The ice crystals formed after partial freezing, act as a template, while the dissolved monomer, cross-linker and initiator are concentrated in a small fraction of an unfrozen liquid phase. Although the frozen monomer system appears homogenous, it is composed of two phases: the solid phase and the unfrozen liquid phase where the polymerization takes place. After polymerization and after melting of ice, many pores are formed in the spaces that were originally occupied by solvent crystal. The morphology of the networks consists of polyhedral pores and the network chains building the pore walls. The gels formed under these conditions were named as cryogels. In this study, by applying the cryogelation technique to the present gelling system, cryogels exhibiting superfast swelling-deswelling kinetics were obtained from 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomer and N,N-methylenebis (acrylamide) (BAAm) crosslinker in aqueous solution at 5 w/v % initial monomer concentration. The crosslinker BAAm content in the monomer mixture was set to 17 mol %. The gel preparation temperature, Tprep, was varied between -22ºC and 25ºC. The swelling, swelling/deswelling kinetics, the morphologies as well as the elastic properties of the gels formed at various temperatures were studied. Tprep was found to be a significant parameter affecting the properties of the hydrogels. Depending on Tprep, two different regimes were observed from the experiments. At Tprep=-8ºC or above, Poly(AMPS) (PAMPS) gels exhibit relatively high swelling ratios Veq of the order of 101, and low moduli of elasticity G in the range of 102-103 Pa. However, decreasing Tprep below -8ºC results in a tenfold decrease in the swelling ratio and about tenfold increase in the elastic modulus of gels. Thus, the swelling and elastic properties of PAMPS drastically change as Tprep is decreased below -8ºC. SEM images of PAMPS networks formed at various Tprep, indicated that all of the polymer samples formed below -8ºC have a porous structure with pore sizes of 30-50 µm while those formed at or above -8ºC exhibit a continuous morphology. Completely reversible swelling-deswelling cycles were obtained using PAMPS cryogels prepared below -8ºC. Gels formed below -8ºC attain their equilibrium swollen volumes in less than 30 sec, while those formed at higher temperatures require about 1 h to reach their equilibrium state in water. Moreover, if swollen PAMPS gels are immersed in acetone, those prepared below -8ºC attain their equilibrium collapsed state in 5 to 10 min, while the hydrogels formed at higher temperatures are too weak to withstand the volume changes. Thus, decreasing Tprep below -8oC results in the formation of superperfast-responsive PAMPS hydrogels, which are also stable against volume changes. Keywords: Hydrogel, swelling, freezing, macroporous
Analysis of the factors effecting organizational survival in Turkey
Get PDFTürkiye'de organizasyonel süreklilik ve organizasyonel ölüm riski arasındaki ilişkinin incelendiği bu çalışmada, organizasyonların yaşam süreleri boyunca ne tür riskler taşıdıkları ve bu risklerin Türkiye'de organizasyonel sürekliliği nasıl etkilediğine açıklık getirilmeye çalışılmıştır. Küçüklük engelleri hipotezlerinin geçerliliği, İstanbul Sanayi Odası'ndan (İSO) alınan faaliyetini sonlandırmış firmalara ait verilerle incelenmiştir. İstanbul Ticaret Odası (İTO) ve İSO'dan alınan kurumsal firma verileri, Kaplan-Meier ve Cox Orantısal Riskler Regresyonu ile analiz edilerek, organizas-yonel ölçek ve organizasyonel yer seçiminin, organizasyonel sürekliliğe etkisi belirlenmeye çalışılmıştır. Öncelikle Kaplan-Meier Yöntemi ile organizasyonel süreklilik ve risk fonksiyonları hesaplanmıştır. Elde edilen organizasyonel süreklilik fonksiyonları arasında, istatistiksel olarak anlamlı bir farkın olup olmadığı Log Rank testi ile incelenmiştir. Hesaplanan organizasyonel süreklilik fonksiyonları arasında istatistiksel olarak anlamlı bir farkın bulunması, ilgili örnek hacmi için incelenen organizasyonel faktörün organizasyonel sürekliliği etkilemiş olduğunun bir göstergesidir. Bu aşamadan sonra, organizasyonel sürekliliğe etkisi incelenen organizasyonel faktörün alt kategorilerinin organizasyonel sürekliliğe göreceli etkilerinin incelenmesi için Cox Orantısal Riskler Regresyonu uygulanmıştır. Elde edilen bulgulara göre; İSO verilerinin analizinde organizasyonel sürekliliğin organizasyonel ölçeğe bağlı olarak değiştiği, İTO verilerinin analizinde ise organizasyonel sürekliliğin organizasyonel yer seçimine bağlı olarak değiştiği görülmüştür. İTO'da faaliyet göstermiş kurumsal firmalar için Eminönü ilçesinin organizasyonel süreklilik açısından en elverişli ilçe, Sultanbeyli ilçesinin ise organizasyonel ölüm riski en yüksek ilçe olduğu tespit edilmiştir. Anahtar Kelimeler: Organizasyonel süreklilik, organizasyonel ölüm riski, Kaplan-Meier yöntemi, Cox orantısal riskler regresyonu.The purpose of this study is to examine the potential risks that Turkish organizations would face during their entire life cycles and to analyze how those risks affect organizational survival and organizational mortality in Turkey. The organizational survival depends on many factors. For different environments, the factors affecting organizational survival might differ. Therefore, it is important to determine these factors for each specific environment. This study aims to highlight the organizational factors affecting organizational survival in Istanbul. Istanbul is the largest city in Turkey in terms of population. Data provided by the Turkish Statistical Institute indicates that in year 2004, throughout Turkey, 15 721 of 40 919 organizations are founded in Istanbul and 3 730 of 7 660 organizations have failed in Istanbul. With this aspect, Istanbul gives a projection of the whole country. The presence of liabilities of smallness for the organizations lived in Turkey is checked according to the data obtained from Istanbul Chamber of Industry. Historical data used in the analysis range from years 1952 to 2006. 11 209 organizations are examined where the mean survival time was 11 271 years. To study the presence of liabilities of smallness, the organizational data are grouped into 3 organizational sizes. The first organizational size is called 'small scale organizations' having 50 and less workers, second organizational size is called 'middle scale organizations' having between 51 and 150 workers and the last organizational size is called large scale organizations' which have more than 151 workers. According to the analysis; the mean survival times are found to be positively related to the organizational scale. Next, the organizational survival and the hazard functions are calculated using Kaplan Meier method. The significance of the statistical difference between the survival functions for the organizational sizes defined is tested with Log Rank test. According to the chi-square value calculated, the difference between organizational survival funtions is significant. This fact allows us to claim that the organizational size is an organizational factor that affected organizational survival of the firms registered at Istanbul Chamber of Industy. We also looked at the pairwise comparisons of the organizational survival funtions for each organizational size. The effect of organizational location on organizational survival is examined with the data of Istanbul Chamber of Commerce. The historical data used in the analysis ranges from years 1902 to 2005. First, the data are grouped into 32 districts that are listed in Istanbul Metropolitan Municipality. The mean survival times are given for each district. The significance of the statistical difference between the survival functions for the organizational locations is tested with Log Rank test. According to the chi-square value calculated, with 95% of confidence the difference between organizational survival funtions is significant. This fact allows us to claim that the organizational location is an organizational factor that affected organizational survival of the firms registered at Istanbul Chamber of Commerce. Next, we wanted to calculate the relative effects of organizational location on organizational survival. Therefore, using cox proportional hazards method, we calculated the cox regression coefficients, values, for each district. The district of Zeytinburnu was chosen to be the refence district. We eliminated the districts that have unsignificant values. Within the significant values, the smallest value was -0.357 for the district of Eminönü and the highest value was 0.491 for district of Sultanbeyli. That means, the district of Sultanbeyli is the least suitable district for organizational survival in Istanbul whereas Eminönü is the most suitable district for organizational survival in Istanbul for the firms registered at Istanbul Chamber of Commerce. As the result, statistical evidence of liabilities of smallness is determined for Istanbul Chamber of Industry firms. Eminönü district is found to have the greatest organizational survival probability whereas Sultanbeyli district is found to have the greatest organizational mortality risk for institutional firms registered to Istanbul Chamber of Commerce. Keywords: Organizational survival, organizational mortality, Kaplan-Meier Method, Cox proportional hazards regression.
Viskoelastik damar dokusunda malzeme parametrelerinin deneysel tahmini
Get PDFThe great majority of diseases in the (western) world, such as atherosclerosis and degeneration of intervertebral discs are diseases of soft tissues. Hence, the multidisciplinary field of soft tissue research is of crucial scientific, medical and socioeconomic importance. The fast progress in the developments of hardware and software facilities makes it possible to thoroughly investigate biological soft tissues and their pathologies on a computational basis. Since soft tissues are biological materials, which fulfill mechanical purposes and adapt to their mechanical environment (growth, remodeling and morphogenesis), it is of fundamental importance to identify the complex interactions of mechanical and biological responses. This work lays out a viscoelastic material model for the arterial tissue. In order to correctly describe the motion of a thick-walled tubular model of an arterial specimen under combined extension, inflation and torsion loads, large deformation kinematics theory is introduced. Lagrangian practice has been applied, which is a general notion in solid mechanics of hyperviscoelastic materials. The material model is introduced in parallel, which is a non-linear three element solid when regarded with a 1-D analog to standard viscoelastic practices. Principle of multiplicative decomposition, a common practice in large deformation plasticity, is successfully applied to get an insight to time-evolution characteristics of the tissue as well as pure elastic response in a decoupled manner. The material elastic stress law and thermodynamically consistent evolution law, namely the stress-strain relations are derived. The arterial tissue which has been modeled as a thick-walled mono-layered axisymmetric cylinder is, when explicitly stated, to be of a type that is called fiber reinforced composite. The governing equations of constitutive assumption are then represented for the fiber-reinforced model. The fiber constituents are mainly the collagen fibers that exist in bundles within a ground matrix material, known to exist mainly in the form of elastin and, within our model, passive existence of smooth muscles. The issues related to fiber-reinforced structure are the evolution of stretch of collagen fibers with ongoing deformation due to external applied loads, and the characteristics of dissipative behavior due to existence of fibers. To cope with experimental practices and realistic simulation of real life situations, the explicit relations between the stress (thus strain) values using the constitutive model and the applied loads, namely the internal pressure, the axial force and the torsional moment are successfully obtained. Due to the thick-walled tube assumption that has been the underlying base to model the arterial tissue, all the quantities had the form of a radial integration of some quantity through the wall thickness of the hollow cylinder at the deformed state, despite the constitutive assumptions have been laid in a Lagrangian manner. Details of the test setup, that has been facilitated at the Laboratory of Strength of Materials and Biomechanics, Faculty of Mechanical Engineering, Istanbul Technical University have been provided to let the readers have an insight of how the experimental system runs. The complexity involved in the loading protocols has required bringing up different sensors and techniques together. The use of high speed video imaging systems for optical strain measurement under dynamic extension, inflation and torsion have been successfully applied to obtain complete experimental data over specimens. Sample pictures and calculations from the optical strain measurement system synchronized to the loading frame control electronics have been provided to clarify the deformation data acquisition process. Parameter estimation has then been carried out with the collected data. Required post-processing of both strain and load data have been carried, preceding the estimation processes. Various scenarios have been applied over a fibrous arterial tissue. Data from these different tests have been analyzed and relevant graphical representations of fitting have been presented. Both quasi-static and dynamic loads up to 10 Hz and up to 100% Lagrangian strains in axial and tangential directions have been applied over the specimens. The observed discrepancies between the experimental and theoretical gatherings have been commented and finally the limitations of the model and the critics to its applicability over modeling the arterial tissue have been stated. Keywords: Biomechanis, experimental mechanics, arterial tissue, nonlinear viscoelasticity.Dünyadaki ekonomik, bilimsel ve tıp açısından oldukça önemli ve gözlemlenme oranı yüksek olan ateroskleroz ve disk dejenerasyonu gibi hastalıklar, temelde yumuşak doku hastalıkları olarak adlandırılabilirler. Bu bağlamda, disiplinler arası bir araştırma konusu olan yumuşak dokularda araştırma, sosyoekonomik olarak gittikçe büyüyen bir önem arz etmektedir. Donanım ve yazılım olanaklarındaki hızlı gelişmeler, yumuşak dokuların ve ilgili patalojilerin sayısal olarak detaylı şekilde modellenebilmesine olanak tanımaktadır. Bu çalışmada, viskoelastik özellikler gösteren damar dokusu üzerinde teorik bir modelin öncelikle matematiksel altyapısı oluşturulmuş ve fiziksel büyüklükler ile gerilme ve/veya şekil değiştirme büyüklükleri arasındaki ilişkiler elde edilmiştir. Yöntem olarak, öncelikle büyük deformasyonlar yapan katıların, Lagrangian esaslara göre deformasyon kinematikleri incelenmiş ve bünye denklemleri elde edilmiştir. Bu ifadeler, temel termodinamik kanunları ile ilişkilendirilerek, üç elemanlı viskoelastik bünye denklemi modeline uygulanmıştır. Plastisite teorisinde yaygın kullanım alanı bulan çarpımsal ayrıştırma prensibi kullanılarak, viskoelastik ve saf elastik davranışlar birbirinden ayrıştırılmıştır. Buradan elde edilen ifadelerle, damar yapısı için önemli büyüklükleri göz önüne alan bir kalın boru modeli için yüklenme ve deformasyon ilişkileri elde edilmiştir. Daha sonra, öngörülen modelin içinde bulunan malzeme parametrelerinin tahmini için kurulan deney düzeneği tanıtılmıştır. Bu esnada yapılan kabullerden bahsedilmiş ve kurulan ölçüm sisteminden elde edilen statik ve/veya dinamik yüklenmelere ait verilerin işlenebilmesi için gerekli detaylar sunulmuştur. Deneysel çalışmalarla, teorik sonuçların karşılaştırılması sonucunda elde edilen bulgular yorumlanmıştır. Anahtar Kelimeler: Biyomekanik, deneysel mekanik, damar dokusu, nonlineer viskoelastisite
Poliamid 6'nın aşınmasında karşı yüzey pürüzlülüğünün etkisi
Get PDFIn this study, effect of counterface roughness on the wear of extruded PA 6 is investigated in dry sliding against stainless steel discs. In a pad on disc wear machine, PA 6 pins were tested against stainless steel discs which had various roughness values. Disc material is AISI 416 C stainless steel (0.15% C, 1.25% Mn, 1% Si, 13% Cr, 0.04% P, 0.03% S). Hardness is 52 HRC. Cylindrical surfaces of discs in 60 mm diameter were used as wearing surfaces. Polymer specimens were produced as cylindrical pins in 10 mm diameter. One of end faces of each pin was formed in the same radius with the discs. In all experiments, normal force and sliding speed is constant. The variable parameter is the surface roughness of the discs. Roughness of the discs were produced by cylindrical grinding. Four different grinding wheels were used. The grain sizes of wheels were 36, 46, 60 and 120. Grain size, diamond dressing rate, grinding time and circumferential speed of the wheel were varied in order to obtain verious counterface roughness values. Circumferential speed was varied using wheels with different diameters without changing the rotational speed. Very high roughness values (mean of profile deviations Ra = 3 mm) were generated by using grinding wheels with smallest possible diameters. Very low roughness values (Ra 1 mm) it was investigated whether wear rate increases with the parameter (1+4m2)1/2/s or not. It was seen that wear rates of PA 6 increase with this parameter. According to the results of experiments it was seen that steady state wear rates increase in the range of axial Ra = 0 - 1.5 mm and decrease in the range of 1.5 - 3 mm, generating a maximum for almost Ra = 1.5 mm. It is estimated that the decrease in wear rate is caused by the continuous transfer film formation on the counterface. Coefficient of friction generally decreases with increasing counterface roughness. In our experiments, when counterface roughness increased coefficient of friction decreased slowly. It is estimated that the observed slow decrease was caused by high coefficient of friction and high temperature. Keywords: Wear, polymer, roughness, fatigue, abrasive wear. Polimerlerin metal karşı yüzeyle eş çalışmasında, aşınmayı etkileyen en önemli faktörlerden biri karşı yüzeyin pürüzlülüğüdür. Bu çalışmada ekstrüzyon PA 6'nın, paslanmaz çelikten disklerle kuru sürtünmesinde, karşı yüzey pürüzlülüğünün polimerin aşınmasına etkisi incelenmektedir. Pürüzlülük silindirik taşlamayla oluşturulmuştur. Çok küçük pürüzlülük değerleri ise (profil sapmalarının aritmetik ortalaması Ra £ 0.15 mm) taşlamanın ardından 280-320 numaralı SiC zımpara kağıdı kullanılarak elde edilmiştir. Disklerin eksenel yöndeki Ra değeri yaklaşık olarak 0.08 mm'den 3 mm'ye kadar değişmektedir. PA 6 papuç-disk aşınma cihazında, farklı yüzey pürüzlülüğüne sahip paslanmaz çelikten disklerle (AISI 416 C, 52 HRC) aşınma deneyine tabi tutulmuştur. Disk malzemesinin alaşımı % 0.15 C, % 1.25 Mn, % 1 Si, % 13 Cr, % 0.04 P, % 0.03 S şeklindedir. Disklerin yüzeyinde pürüzlülük ölçümleri yapılarak standart pürüzlülük parametreleri elde edilmiştir. Pürüzlülük profillerinden ortalama tepe yuvarlaklık yarıçapı Rav sayısal analizle hesaplanmıştır. Disk yüzeylerinin optik mikrofotoğrafları çekilmiştir. Deneyler sonucunda, ekstrüzyon PA 6'nın karşı yüzeyde sürekli bir transfer filmi oluşturduğu, eksenel Ra = 0-1.5 mm aralığında aşınma hızının arttığı, 1.5-3 mm aralığında ise aşınma hızının azaldığı görülmüştür. Ayrıca karşı yüzeyin Ra = 0-1 μm aralığında, transfer filmi oluşumu sebebiyle, aşınma hızının Rav ile değişiminin Hollander ve Lancaster'in yorulma aşınması modeline uymadığı tespit edilmiştir. Deney sonuçlarının, eksenel Ra = 1-3 mm aralığında, polimerin kopma mukavemeti, sürtünme katsayısı ile abrazif aşınma hızı arasında bir bağıntı veren abrazif aşınma modeline uyduğu görülmüştür. Anahtar Kelimeler: Aşınma, polimer, yüzey pürüzlülüğü, yorulma, abraziv aşınma. 
Yer bilimlerinde servis odaklı mimari ile coğrafi bilgi sistemi oluşturulması
Get PDFYerkabuğu deformasyonu çalışmaları, tekrarlı jeodezik ölçmelerin analizi ve bunların jeolojik ve jeofizik araştırmalardan elde edilen sonuçlar ile birlikte değerlendirilmesine dayanır. Bir disiplinin ürettiği sonuç, diğer bir disiplinin girdi verisi olduğundan, tek tip veri üreten bir çalışmanın, diğer çalışmalardan üretilmiş değişik tipteki verileri kendi verisi ile entegre etmediği sürece anlamlı bilgi üretemeyeceği açıktır. Bu da göstermektedir ki, çözülmesi gereken problem doğal olarak disiplinlerarası bir karaktere sahiptir. Ancak yer bilimciler genellikle problemin bir yanı üzerine çalışmakta ve sadece istendiğinde verisini paylaşma eğilimindedirler. Bu nedenle kaynaklar, tekrar tekrar aynı çalışmalar üzerinde boşuna harcanmış olmaktadır. Halbuki günümüzde verinin mümkün olduğu kadar çabuk ve efektif olarak bilgiye dönüşmesi gerekmektedir. Bunu gerçekleştirebilmek için hesap ve analiz ortamlarının araştırmacıların, karar vericilerin ve eğitimcilerin masaüstü bilgisayarlarına taşınmış olması gerekmektedir. Bu çalışmanın amacı, çok disiplinli yer bilimleri verilerini, araçlarını ve yazılımlarını birbirine bağlayan ve paylaşımını sağlayan servis odaklı mimari yapıda bir Coğrafi Bilgi Sisteminin oluşturulması ve bu sisteme farklı seviyelerde kullanıcıların (bilimadamı, eğitimci, karar verici vd.) ulaşımının sağlanması ve böylece Türkiye’de depremler ile ilgili çalışma yapmak isteyenlerin, kolay kullanım arayüzü ile interaktif olarak veriye, hesap ve analiz ortamına ulaşmasının sağlanmasıdır. Servis odaklı mimari farklı işletim sistemleri ve platformlarda çalışan ve farklı programlama dilleri ile yaratılmış uygulamalardan elde edilecek dağıtık bilginin belli amaçlar için biraraya gelmesini sağlayan bir çözümdür. Anahtar Kelimeler: Coğrafi bilgi sistemi, servis odaklı mimari, internet, yer bilimleri.The studies of recent crustal movements are based on analyses of repeated geodetic measurements, and their combination with results of geophysical and geological investigations. It is obvious that a single data producer can not produce useful datasets and information without integrating data from others because one scientist's results become another's data. So, the problem to be solved naturally has an interdisciplinary character. However, earth scientists traditionally work on one aspect of the problem and they have a tradition of sharing of data but they are willing to share it if asked. Because of this, the resources are being wasted in duplicative efforts. However, the goal is for data to evolve it into information, and then into knowledge as quickly and effectively as possible. In order to do this, calculations and analysis need to bring to the desktops of researchers, decision-makers, and educators. The aim of this study is to develop a service-oriented architecture (SOA) based Geographic Information System (GIS) that enables linking and sharing multidisciplinary earth science data, tools, and software and to provide a wide range of users access to the system and in this way to build an easy-to-use interactive access to data and analysis environment to study earthquakes in Turkey. In this study, a system was developed to access the earth science data that is available now and data which will be coming online, and to provide users easy access to computation and visualization tools. This study is a motivation for developing the necessary information technology infrastructure applicable to earth science areas. It speeds up the scientific discovery process. It is scalable to accommodate future growth and changes since the framework is based on the service oriented architecture. This architecture allows the modules to be written in separate programming languages, and to be run on different computers over the Internet. GIS is used as a user interface. The functional requirements of the system are the various information technologies. It includes many types of data and algorithms from the field of the earth sciences, computers, GIS, networking and databases. In the study, several software tools are used for processing input data, storing them, and presenting on the web. Most of them are open source programs. Therefore, this study shows the usability of open source software in earth science studies. The study represents a system for calculating strain and analysis of outputs. There are different kinds of methods to obtain strain. Geodetic methods of repeated determination of position are used to obtain and monitor strain accumulation and analysis. The results are affected by the determination of the small regions in which the strain is assumed as homogeneous. In this study, strain from geodetic velocities and also from seismic data is obtained. Seismic hazard assessment depends on the ability to understand where strain in the Earth's crust is accommodated and how much of this strain is accommodated seismically. So strain rate maps can be used to visualize the present day deformation of Earth's crust. In the method used, the model grid is continuous in longitudinal and latitudinal directions and covers the study area, Turkey, between 30°N and 45°S and between 20°W and 45°E. The model is calculated on a regular grid. Each grid area is 0.5° x 0.5° in dimension whether an area is considered to be deforming or not is based primarily on seismicity occurrence. This study involves the development of an Internet based system that brings together data, tools, computations and users in a single efficient framework to be used for earthquake related application. A portal based architecture has been adopted in the user interface and service oriented architecture in the middleware. Portals provide users with a single point of access to the system. They also provide a dynamic environment and interactive capabilities. The benefits of this architecture include flexibility and scalability. It also promotes reusability of components. This minimizes the need for new coding. One of the main advantages of Web services is that it does not raise issues of firewalls since it can support any communication protocol. Furthermore, Web services can significantly reduce the data volume and computing resources at the user side. Web services are considered as the next generation of distributed systems because of their advantages such as interoperability. Keywords: Geographic information system, service oriented architecture, internet, earth sciences
The visualisation with being theory in Location-Based Services
Get PDFSon yıllarda, Konum Destekli Hizmetler (KDH - Location Based Services), cep telefonları ve avuç içi bilgisayarları gibi mobil cihazların ekran ve işlemci kapasitesinin gelişmesi ile ön planda yer almıştır. Mobil cihaz kullanıcısının talepleri doğrultusunda anlık konum bilgilerinin ölçülmesi, değerlendirilmesi ve sunumu, tüm gelişmelere rağmen özellikle cep telefonlarındaki kısıtlı donanım yapılandırması sebebiyle çözüm gerektiren bir konudur. GPS ve diğer özel algılayıcıların günlük hayatımıza girmesi ile bilgisayarlar tarafından insan davranışlarının belirli düzeyde tespit olanağı sağlanmıştır. Bu da uygun modellemeler ile durum duyarlı uygulamalara imkân vermektedir. İnsan-bilgisayar ilişkisi çerçevesinde bilgisayarların insan dilini anlayamaması birçok konuda sorun yaratmaktaydı. Bu durum bilgisayar bilimlerinde anlamsal (semantik) yaklaşımlar ile aşılmaya çalışılmıştır. Anlamsal bilgisayar dilleri hem insanın hem de makinelerin anlayabileceği bir dil üretmiştir: OWL (Ontology Web Language). Bu dil, varlık felsefesinden doğan “ontoloji” (varlık teorisi) ile, internet dünyasındaki devasal web bilgi yığınını bilgisayarların anlayacağı bir duruma getirmek maksadıyla ortaya konulmuştur. Daha sonrasında tanımsal mantık (description logics) ile desteklenmesi ile durum-duyarlı uygulamalar için neredeyse bir standart halini almıştır. Bu çalışmada çevresel durum duyarlı (context-aware) bir görselleştirme için küme tasarımı ve üretim aşamaları açıklanmaktır. Varlık modelinin oluşturulabilmesi için öncelikle mekânsal veri türlerinin varlıksal tanımları ve birbirleri arasındaki ilişkileri ortaya konmuştur. Çevresel durum duyarlı uygulamaların en önemli gereksinimi tutarlı bir kontext modeldir. Bu modelin tutarlılığı uygulamanın değişik durumlara karşı olan duyarlılık hassasiyetini belirler. Anahtar Kelimeler: Ontoloji, mekansal veri, Konum Destekli Hizmetler (KDH), görselleştirme. Recently, the visualization of spatial data has been gaining importance in ubiquitous computing. In Geoinformatics, such as distributed GIS or Location-Based Services, context models are responsible for the robust communication between the mobile user and the system. "Context" and "context awareness" are the key notions in realisation of the situational information. Context is information characterising the situation of an entity and one of the important entities of the context definition itself is "person". A well-defined context-aware system should fulfil the user's task appropriately. Context-aware systems are a serious consideration in ubiquitous systems and these systems reflect the delicate effect of the designed context. An efficient contextual system needs ontologies. Characteristics of chosen ontology languages determine not only the achievement of the representation of the context but also the capabilities of its reasoning. Ontology Web Language (OWL), an improved version of the DAML+OIL Web Ontology Language, particularly enables description logic support. Description Logics (DLs) allows knowledge representation with concept descriptions and role constructors. OWL-DL is the preferred subset of the OWL to provide reasoning in a well-defined way. To develop a user-adaptive ontological model, users' different situations should be defined properly. In Location-Based Services (LBS), a very intelligent system ignores the effect of user's states and roles except the user's location. Customised visualisation style, however, needs different user profiles in order to provide relevant spatial data. In the computer and cartographic sciences, individual and short-term usage have brought about term of egocentric maps for mobile devices. Design patterns of egocentric maps satisfying user's ego-centre determine visualisation parameters such as centring, redundant encoding, continuous varying of level of details, multiple levels of details, space contraction, single window with details on demand, augmented focusing, orientation gesture and affective emphasis. The aim of this research is to define mobile contextual ontologies (classes and properties) which obey relevance theories so as to define any user's relevant visualisation profile on the mobile devices. The kind of intelligent system proposed here can therefore reason over the complete semantic model of the OWL language by an inference engine. A contextual ontology (OWL-DL) for relevancy has been edited in an ontology editor and knowledge acquisition system. Consequently, the inference engine retrieves criteria for relevant visualisation profiles with its reasoning algorithms or defined SWRL (Semantic Web Rule Language) as a server. In the article, the visual parameter concept has been added to the upper context model to state the visual components of the spatial data as an important part of the system. Data type properties of the visual parameter concept have also been placed on the upper ontology. Subconcepts of the visual parameter have been defined as line and node. The relation between a concept and a subconcept is "is a" relation. Therefore, it can be stated that a line is a visual parameter and a node is a visual parameter. Actually, spatial data can be represented in three main geographic features: point, line and polygon. In the research, the polygon feature has been eliminated while representing spatial data. All polygonal data have been converted to the central point of it because of the limited display size of the mobile devices. Consequently, the visualization has been realized as the line and the node. Egocentric design of a Map-based service which provides relevant visualisation for mobile users is implemented in the campus area of the Istanbul Technical University. Implementation of the service is intended to test consistency of the proposed model for the real user world. A multi-tier technological architecture has been designed that includes spatial database, knowledge base and web map server (WMS). To connect the mobile devices to the servers, a web server and a proxy server have also been set up as in the middleware architecture. GPRS connection, that is the only wireless connection provided by the mobile phone operators, has been used in the research. The UMTS has not been provided yet in Turkey. A GUI that collects information from mobile users has been designed. The architecture has been composed with Java 2EE and Java 2ME programming. To implement the inference procedure the semantic query language (nRQL) has been used. Keywords: Ontology, spatial data, Location-Based Services (LBS), visualisation
Marmara Denizi'nde son buzul döneminden günümüze deniz seviyesi değişimleri
Get PDFHigh-resolution reflection seismic profiles and core analyses of sedimentary sequence near the Sea of Marmara (SoM) entrance to the Strait of İstanbul (SoI, Bosphorus) provide detailed record of sealevel changes since the Late Glacial Maximum (LGM). The sequence is deposited over the LGM erosional surface at a maximum depth of -105 m. It includes seven seismic units that can be confidently correlated with 14C-dated (uncalibrated) sedimentary units in the cores. Unit-S1f consists of conformable beds constituting a ridge-like future in the middle of the main channel and dipping in opposite directions. We interpret this unit as a levee deposited in the main paleo-strait’s channel. The lowermost 175 cm part of Core MD-2750 represents the upper part of the levee deposit (Unit-S1f), which comprises silty and sandy beds with marine molluscan shells. This unit is differentiated from the overlaying other units by its relatively coarse-grained nature. Unit-S1f represents levee deposits of the paleo-SoI channel that was deposited by a Black Sea outflow during 12000-10 600 yr BP. The levee unit is overlaid by Unit-S1e over ersoional surface E, which corresponds to the onset of the early Holocene Sapropel (Çağatay et al., 2000) as indicated by high Corg values (>1.5 wt%) and its stratigraphic position in Core MD-2750. This sapropelic layer was previously dated 10 600-6400 yr BP by Çağatay et al. (2000). Its onset age is consistent with the 14C ages of 10 950 yr BP and 10 450 yr BP obtained below and above truncation surface E, therefore, age of the reflector E can be estimated as 10 600 yr BP. The reflection surfaces at the base of Unit-S1d and S1c correspond to wave-cut terraces at -71 and -63 m, respectively, and are estimated to be 10 600 and 9800 yr BP. The seismic Unit-S1b comprises deltaic sediments that were deposited during 6400-3200 yr BP. Isopach map and forset directions of the deltaic unit indicate that the delta was sourced from Kurbağalıdere River. Contrary to the interpretations of Hiscott et al. (2002) and Gökaşan et al. (2005) that this deposit formed during the course of a rapid sealevel rise, our dating places its growth after sealevel had nearly reached its modern level about 6500 yr BP. As mapped out in plan view the outline of the topsets and foresets of Unit-S1b coincides well with the same deposit mapped by Gökaşan et al. (2005). We propose the following sequence of events leading to the delta formation. According to global sealevel curves (e.g. Fairbanks, 1989), the rate of sealevel rise decreased after 6500 yr BP. This decrease combined with an increase in sediment supply during mid-Holocene climatic optimum resulted in the deltaic progradational sedimentation on the shelf of southern enterance of SoM to SoI. This conclusion is in agreement with the fact that the mid Holocene is a well known period for widespread delta development (Stanley and Hait, 2000). The change from the progradational stage to the aggradational stage of delta development at 4700 yr BP is marked by a relatively rapid rise of sealevel as indicated by climbing delta foreset-topset transition. The onset of aggradational period also coincides with establishment of the present dual-flow regime (Çağatay et al., 2000) with the Mediterranean under-current in the SoI, forming a northward sediment drift. The delta deposition was terminated when increased base level due to further global sealevel rise combined with a probable decrease in sediment input by the Kurbağalıdere River at 3200 yr BP. This date is supported by the correlation with the age of the late Holocene Sapropel layer and by a 14C age of 4400 yr BP in Core TSU03-13 below the eroded uppermost topsett bed. The Kurbagalıdere River, with a present day annual water and sediment discharges of 80 m³ and 60 000 tons (EİE, 1993) draining a 180 m high ground southeast of the SoI, is large enough to form such a delta having about 290 x 106 tons of sediment. In this study, we present detailed seismic stratigraphic analysis of high resolution shallow seismic lines crossing an area near the southern entrance of SoI, together with the core stratigraphy. Our main objectives are to discuss the chronostratigraphic evolution of the Holocene sediments including delta formation in the paleo-SoI channel, and shed light on the water exchange problem between the Marmara and the Black Seas during the Holocene (last 12 000 years). Keywords: Marmara Sea, core stratigraphy, seismic stratigraphy, sealevel changes, delta, sapropel. Marmara Denizi İstanbul Boğazı girişinde yeralan sismik profil ve karotlarda yapılan ayrıntılı stratigrafik ve kronolojik çalışmalar Son Buzul Maksimum (Late Glacial Maximum) döneminden günümüze deniz seviyesi değişimlerini ortaya çıkarmaya yardımcı olmuştur. Bu dönem süresince Marmara Denizi’nde çökelen birimler -105 m su derinliğine kadar yüzeyleyen uyumsuz yüzey üzerinde çökelmiştir. Sismik profillerde yapılan stratigrafik çalışmalarda 7 farklı sismik birim ayırtlanmış ve bu birimleri ayıran 7 sismik yansıma yüzeyi belirlenmiştir. Sismik profillerde ayırtlanan birimlerin yaşları ve fasiyesleri karotlardan alınan 14C yaşları ile saptanmıştır. Sismik profillerde ayırtlanan en yaşlı çökel birimi Birim-S2 olarak tanımlanmıştır. Bu birim Holosen (G.Ö. 12 bin yıl öncesi) öncesinde Marmara Denizi’nde başlayan transgresyon sonucunda vadi-dolgusu fasiyesinde gelişmiştir. Bu transgresyon ile göl seviyesi yükselerek -81 m’ye ulaştığı Birim-S2’yi üzerleyen sismik yansma yüzeyi üzerinde gelişen taraça düzlüklerinin varlığından anlaşılmaktadır. Birim-S2’yi uyumsuzlukla üzerleyen Birim-S1f kanal-bank kenarı çökelleri olarak yorumlanmıştır. Holosen içerisinde Karadeniz’den Marmara Denizi’ne G.Ö. 12 000-10 600 yılları arasında su akışı sonucu İstanbul Boğazı paleo-kanalı içerisinde bu çökeller oluşmuştur. Ayırtlanan Birim-S1d ve S1c’nin tabanlarını oluşturan sismik yansıma yüzeyleri -71 m ve -63 m’lerde gelişen kıyı aşındırma düzlüklerini temsil etmektedir. Holosen başı olan G.Ö. 12 bin yılında deniz seviyesinin yükselmeye başlamasının ardından bu durağan deniz seviyesi dönemleri G.Ö. 10 600 ve 9800 yıllarında gelişmiştir. Sismik birimlerden Birim-S1f’in eğimli klinoform tabakalar içermesi bu birimin delta çökeli olduğunu göstermektedir. Delta çökellerinde bu çalışma kapsamında yapılan sismik stratigrafik ve kronolojik çalışmalara göre G.Ö. 6400 ile 3200 yılları arasında çökeldiği tespit edilmiştir. Bu çökellere ait yapılan kalınlık haritası ve foresetlerin eğim yönleri bu deltanın Kurbağalıdere Nehri’nden geliştiğini göstermektedir. Anahtar Kelimeler: Marmara Denizi, karot stratigrafisi, sismik stratigrafi, deniz seviyesi, delta, sapropel
The investigation of the inability to distinguish among the coniferous forest species using hyperspectral satellite image
Get PDFGünümüzde çağdaş ormancılığın amacı, ormanın sürekliliğini sağlayarak optimum yararlanmayı temin etmektir. Dolayısıyla ormanın verimi, sürekliliği ve korunması için yürütülen gençleştirme, bakım, ağaçlandırma gibi ormancılık faaliyetlerinin en iyi şekilde gerçekleştirilebilmesi için orman alanlarına ait bilginin güncel olması gerekmektedir. Son yıllarda teknolojinin gelişmesi ile birlikte ucuz ve hızlı sonuç alınabilinen uzaktan algılama tekniğinin ormancılık çalışmalarında önemi giderek artmaktadır. Bitki örtüsünün çok bantlı uydu görüntüleri ile izlenmesi literatürde en çok kullanılan yöntemlerden birisidir. Son zamanlarda objelerin ayırt edilebilirliklerini arttırarak daha iyi sonuçlar elde etmek amacıyla hiperspektral veya görüntü spektroskopisi olarak adlandırılan birçok yeni algılayıcı geliştirilmiştir. Objelerin spektral karakteristikleri sürekli ve daha çok spektral bantlara sahip olan hiperspektral uydu görüntüleri ile daha iyi belirlenmektedir. Bu çalışmada da Sündiken Kütlesi’ndeki ibreli orman türleri EO–1 Hyperion hiperspektral uydu görüntüsü (17.09.2004) ile ayırt edilmeye çalışılmıştır. Sündiken Kütlesi’nde baskın olarak saf ibreli orman türleri ve bunun yanında meşe ile ibreli ağaç türlerinin birlikte yetiştiği karışık orman alanları bulunmaktadır. Çalışmada yer ölçmelerine bağlı olarak Hiperspektral uydu görüntülerinden elde edilen test alanlarına ait spektral eğriler kullanılarak SAM (Spectral Angle Mapper) algoritması ile sınıflandırma işlemi yapılmıştır. Elde edilen sonuçlar Karaçam (Pinus nigra) ve Sarıçam (Pinus sylvestris) ağaç türlerinin spektral özelliklerinin çok benzer olması sebebiyle birbirinden ayırt edilebilirliğinin zayıf, Kızılçam’ın (Pinus brutia) ise ayırt edilebilirliğinin yüksek olduğunu göstermiştir. Anahtar Kelimeler: Uydu görüntüsü, hiperspektral, sınıflandırma, orman, ibreli.In nowadays, the principal goal of modern forestry is to provide the capacity to be useful itself of the sustainability of forest. Consequently, current information on areas of forest should be reached in order to realize the services of forestry like the regeneration, the forest tending, and the forestation which are carried out in order to contribute to the productivity, continuity, and the protection of the forests. With recently developed technology, the remote sensing providing of the cost-effective, reliable and fast results obtains the significance information on the forest applications. Vegetation monitoring using broad band multispectral remote sensing is well established. Recently, many new sensors are being developed to increase the discrimination ability of the objects, such as the acquisition of hundreds of narrow band spectra, termed hyperspectral remote sensing or imaging spectroscopy. Imaging spectroscopy refers to data acquired by an airborne or spaceborne imaging spectrometer and the analysis techniques applied to these data in ways that exploit the instrument's ability to resolve absorption features caused by the chemical bonds and physical structure of surface materials. In comparison to the handful of channels available with multispectral, broad band remote sensing, imaging spectrometers measure the radiation upwelling from a surface in hundreds of contiguous, narrow band width channels. The advantage offered by such spectroscopic measurements is the ability to resolve absorption features and determine their specific wavelength positions and characteristic shapes. These absorption features can be related to the material or materials causing them; thus, the materials occurring in a pixel of imaging spectroscopy data can be identified. In this study, the coniferous forest tree species were tried to be distinguished by using hyperspectral image taken by the EO-1 Hyperion at Sundiken Mountain, Turkey. The Sundiken Mountain is strongly covered with pure coniferous forests as well as mixed stands with deciduous trees. The dominant deciduous trees are oak (Quercus spp.), occurring in mixed stands with pine species stands. Anatolian Black Pine (Pinus nigra), Turkish Red Pine (Pinus brutia) and Scots Pine (Pinus sylvestris) are the dominant naturally-growing coniferous trees. Anatolian Black Pine and Turkish Red Pine occurs mixed with the oak trees. The spatial distribution of forest species on the Sundiken Mountain is changing related to the altitude and aspect. The intemperate forests at high elevations in the region receive large amounts of precipitation during the long, cold winter. At lower elevations, in Sundiken's relatively temperate valleys, Turkish Red Pine and oak trees communities predominate. In addition to altitude, the aspect has an influence on the distribution of plants within the mountain.The atmospheric and the topographic effects in the EO-1 Hyperion image, used in this study, were corrected and converted to reflectance values using the ATCOR-4 (ATmospheric CORrection ) program. Hyperion collects data in 224 contiguous channels of approximately 10-nm bandpass over the spectral wavelength range of 0.35?2.50 µm (from visible light to near-infrared). The missing portions of the spectrum have low signal to noise due to strong atmospheric water vapour absorption, and are not used in subsequent calculations. In Sundiken, for the mean elevation of 1500 m, the Hyperion sensor measured pixels with a nominal size of 30 m at nadir view. The sensor swath width was approximately 7.5 km. Hyperion data were acquired on September 17, 2004, at approximately 10:20 a.m. local time. Our goal is to measure the ability to distinguish related to the spectral variability of coniferous types using hyperspectral data. To do this, the measurements of band depths for chlorophyll and leaf water content of each forest types obtained from hyperspectral image are examined. Finally, we classified the hyperspectral image using the spectral angle mapper (SAM) classification algorithm and compared directly to the ground truth. The Spectral Angle Mapper is a technique to classify hyperspectral data by determining the similarity between an endmember spectrum and a pixel spectrum in an n-dimensional space. Smaller angles represent closer matches to the reference spectrum. Image-based end member spectra of the main land cover types and tree species in the test area are used as input for the classification. The results obtained from the classification showed that the distinction of Turkish Red Pine from other species is satisfied while to distinguish the tree species of Anatolian Black Pine and Scots Pine are weak; because their spectral properties are very similar. Keywords: Satellite images, hyperspectral, classification, forest, coniferous
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