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Öğe Physical and chemical degradation of grassland soils in semi-arid regions: A case from Central Anatolia, Turkey(Elsevier Ltd, 2016) Korkanç, Selma Yaşar; Korkanç, MustafaThe aim of this study is to determine some hydro-physical and chemical characteristics of soils on the grassland areas under semi-arid conditions in terms of soil degradation processes. Three sampling plots of 20 x 20 m size were selected from the Emen Plain as Locations-I, II and III basing on the area covered with vegetation and visual soil properties; and total 108 soil samples from 2 points and 3 depth levels (0 20 cm, 20-40 cm, 40-60 cm) of each sampling plot. Soils of the research area are in degradation process in terms of some physical and chemical characteristics. It was observed that soil properties (i.e. bulk density, total porosity, organic matter, pH, electrical conductivity and saturated hydraulic conductivity) in Location-II and Location-Ill changed negatively in comparison to Location-I almost at all depths. In the Location-Ill grassland, bulk density, pH, electrical conductivity and Na + values are higher than those in Location-I, whereas the organic matter, total porosity and saturated hydraulic conductivity values are low. Grassland area is vulnerable to erosion. High Exchangeable Sodium Percentage (ESP) values in Locations-II and III indicates the sodicity problem in these areas. (C) 2016 Published by Elsevier Ltd.Öğe Secondary structure and conformational change of mushroom polyphenol oxidase during thermosonication treatment by using FTIR spectroscopy(ELSEVIER SCI LTD, 2017) Baltacıoglu, Hande; Bayındırlı, Alev; Severcan, FerideTo understand the conformational changes of mushroom PPO, the secondary structural change of the enzyme during thermosonication treatment at different power (60, 80 and 100%), temperature (20-60 degrees C) and time (0-30 min) combinations was investigated by using FTIR spectroscopy and compared with the change in enzyme activity. The enzyme inactivation higher than 99% was obtained at 100% amplitude at 60 degrees C for 10 min. FTIR studies showed that marked spectral changes were noted after ultrasound treatment at 20 degrees C. The alpha-helix and beta-sheet contents decreased, while aggregated beta p-sheet, turns and random coil contents increased as temperature increased up to 60 degrees C during thermosonication treatment for 10 min indicating protein denaturation. Aggregated bands located at 1683 and 1616 cm(-1) became evident after ultrasound treatment at 40 degrees C. When temperature was lowered back to 25 degrees C, from ultrasound treatment at 60 degrees C, these bands were still observed, indicating the irreversible change in the structure. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Application of lactococcin BZ and enterocin KP against Listeria monocytogenes in milk as biopreservation agents(Akademiai Kiado Rt., 2016) Yıldırım, Zeliha; Öncül, Nilgün; Yıldırım, Metin; Karabıyıklı, ŞenizThis study was performed to evaluate the effect of lactococcin BZ and enterocin KP against Listeria monocytogenes ATCC 7644 in skim (0.1%), half (1.5%), and full fat (3.0%) UHT milks. The milk samples were inoculated with L. monocytogenes at the level of approximately 2.60, 4.76, and 6.45 log CFU ml(-1), and then treated with various concentrations (400, 800, 1600, or 2500 AU ml(-1)) of lactococcin BZ, enterocin KP, or their combination (1: 1). Lactococcin BZ at 400-2500 AU ml(-1) level displayed strong antilisterial activity, and decreased the viable cell numbers of L. monocytogenes to an undetectable level in all types of milk samples during the entire storage periods at 4 degrees C or 20 degrees C. Enterocin KP also had a high antilisterial effect, but it decreased as both the fat content of milk and inoculation amount of L. monocytogenes increased.Öğe Estimating specific energy from the brittleness indexes in cutting metallic ores(South African Institute of Mining and Metallurgy, 2016) Çomaklı, Ramazan; Kahraman, Sair; Balcı, Cemal; Tumaç, DenizSpecific energy (SE) is a very useful parameter for assessing rock excavation by machine. Predicting the SE from the brittleness will be practical, especially for preliminary studies, due to the fact that determining the SE from cutting tests is difficult and expensive. In this study, the predictability of the SE from different brittleness concepts was investigated for metallic ores such as chromite, haematite, galena, and smithsonite. Uniaxial compressive strength, Brazilian tensile strength, impact strength, and small-scale cutting tests were carried out in the laboratory. The SE values were calculated from the cutting tests and correlated with three different brittleness concepts. A significant correlation could not be found between the SE and the brittleness B-3 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength). However, strong correlations were found between the SE and the both brittleness B-5 (the product of percentage fines in the impact strength test and compressive strength) and brittleness B-8 (half of the product of compressive strength and tensile strength). The validations of the derived equations were also checked. It is concluded that the SE in ore cutting can be reliably estimated from the brittleness concepts B-5 and B-8.Öğe Divriği (Sivas) demir yatağının mineralojisi ve oluşum modeline yeni bir yaklaşım(1997) Çopuroğlu, ibrahimİnceleme alanı Toros kuşağının kuzeydoğu bölümünde, Kuzey Anadolu Fay Zonu ile Doğu Anadolu Fay Zonunun kesiştiği alanda yer almaktadır. Buradaki kayaçlar, Üst Kretase'den başlıyarak Pliosen'e kadar devam eden magmatizmanın ürünleri olup, altta ofiyolitik seri ve kristalize kireçtaşları ile üstte kalkalkali asidik, nötr ve bazik karekterli derinlik ve yüzey kayaçları bulunmaktadır. Divriği A-B Kafası manyetit yatağı, % 55 ortalama Fe tenörlü ve 53 milyon ton görünür, 20 milyon ton da muhtemel rezervli olup, felsler içerisinde damar, damarcık ve cep dolgusu şeklinde oluşmuştur. Yatağın birincil mineral parajenizini, manyetit, hematit, pirit, kalkopirit, pirotin, ilmenit, ilmenomanyetit, rutil-anatas, bravoit, arsenopirit, sfalerit ve nabit altından ibaret cevher mineralleri ile skapolit (birincil), diyopsid, biyotit, apatit, epidod, klorit, karbonatik mineraller ve kuvars'dan ibaret gang mineralleri temsil etmektedir. Yatağın mineral parajenezine ait manyetit, skapolit, diyopsid, biyotit ve apatit minerallerinin birbirlerinin içerisinde kapanımlar halinde bulunmaları, manyetit, pirit ve kalkopiritin bünyesinde ancak yüksek sıcaklıkda bulunabilen iz elementlerin varlığı ve hematitlerin mikroskop altında akma dokusu göstermeleri, bunların aynı magmadan ve aynı zamanda oluştuklarına işaret etmektedir. Ayrıca, klorit, epidot, Na-skapolit, karbonat ve kuvarsın varlığı; su oranı yüksek ve akıcı özelliği yüksek, alkali karekterli spilitik cevher magmasına işaret etmektedir. Dalma-batma işleviyle oluşan bu magma ofiyolit serisine ait gabroikler içerisine nüfuz ederek onların içine yerleşmiş, bu arada da uçucu gazları yankayacı felsleştirmiştir.Öğe Influence of addition of different amounts of black carrot (Daucus carota) on shalgam quality(WFL Publisher Ltd., 2014) Tangüler, Hasan; Gunes G.; Erten H.Shalgam (salgam), is a traditional Turkish lactic acid-fermented beverage. It is produced from the lactic acid fermentation of black carrot the main raw material, rock salt, sourdough, bulgur flour, turnip, and drinkable water. The aim of this study was to evaluate the influence of addition of different amounts (10%, 12.5%, 15%, 17.5%, and 20%) of black carrot (Daucus carota) on shalgam quality using traditional method. According to the results, increasing the quantity of black carrot rose the levels of total acidity, solids, ash, colour intensity, total phenolic compounds (OD280) and colour index. There was significant relation between the amount of black carrot used and the amount of those substances. The total acidity expressed as lactic acid varied from 4.95 to 7.45 g/L and pH from 3.39 to 3.49 at the end of fermentation. Total lactic acid bacteria, total mesophilic aerobic bacteria and total yeast counts reached generally maximum numbers on the 4th day of fermentation, then a decrease was observed. Coliform bacteria gradually declined during the fermentation. No coliform bacteria were isolated at the end. According to sensory evaluation, the most preferred samples were 17.5% and 20% carrot additions, whereas, sample A with 10% of black carrot did not have an overall acceptance. Increasing amount of black carrot increased to overall acceptability of shalgams by all panelists. Eventually, it could be stated that black carrot must be used at least in the rate of 15% for the production of shalgam beverage. That amount will reduce production costs of manufacturers.Öğe Computation of time delay margins for stability of a single-area load frequency control system with communication delays(World Scientific and Engineering Academy and Society, 2014) Sönmez, Şahin; Ayasun, Saffet; Eminoğlu, U.Time delays have become unavoidable in power systems since communication links are extensively used for sending and receiving control signals. This paper investigates the effect of time delays on the stability of a single-area load Frequency Control (LFC) system. A direct and exact method to compute delay margins is presented. The delay margin is the maximum amount of the time delay that the system can tolerate before it becomes unstable for a given operating point. The proposed method starts with the determination of all possible purely imaginary characteristic roots for any positive time delay. To achieve this, Rekasius substitution is first used to convert the transcendental characteristic equation of the LFC system into a polynomial. Then, Routh stability criterion is applied to determine the critical root, the corresponding oscillation frequency and the delay margin for stability. For a wide range of controller gains, delay margins of LFC system are determined to find out the qualitative effect of controller gains on the delay margin. Finally, theoretical delay margin results are verified by using the time-domain simulation capabilities of Matlab/Simulink.Öğe Traverten çökelten Tuzlusu (Aksaray) sıcak ve mineralli su kaynaklarının hidrojeokimyasal ve izotopik açıdan incelenmesi(2000) Afşin, Mustafa; Elhatip, HatimTuzlusu sıcak ve mineralli su kaynakları, Aksaray'ın KB'sında Tuzgölü fay zonuna paralel ve buna verev fayların kesişme noktalarında yer alırlar. Kaynakların akiferini oluşturan Bozçaldağ metamorfitlerine ait mermerlerin bir bölümü Çal mevkiinde yüzeylenmektedir. Kaynak sularının toplam debisi düşük, CO2 ve toplam çözünmüş madde (TDS) miktarları ise yüksektir. Tuzlusu kaynak alanında ana fay boyunca yer alan eski travertenlerin yanısıra, sıcak ve mineralli suların aktığı yerlerde yeni traverten çökelimleri devam etmektedir. Traverten çökeliminde kanaldaki su kalınlığının az olmasının yanısıra, türbülan akım, CO2 gazı kaybı, pH ve sıcaklığın yüksek olmasının da önemli rolü vardır. 18O, 2H, 3H izotop verilerine göre meteorik kökenli olan Tuzlusu kaynakları, dolaşım yolu boyunca sokulum yapan granitleri ve evaporitli birimleri yıkayarak yeryüzüne ulaşmış ve sıcaklığını bir miktar kaybetmiş olabilir. 13C analiz sonuçlarına göre ise, kaynak sularındaki karbondioksitin bir bölümü denizel karbonat kökenlidir. Na-Ca-CI-HCO3 ve Na-Cl tipi su kimyası fasiyeslerine giren kaynak sularının hazne kaya sıcaklığı 115°C dolayındadır. Sertliği ve tuzluluk tehlikesi çok yüksek olan bu suların sulama suyu olarak kullanılması uygun değildir.Öğe Lyapunov stability theory based complex valued adaptive filter design [Lyapunov kararlilik teorisi tabanli kompleks degerli adaptif filtre tasarimi](IEEE Computer Society, 2014) Mengüç, Engin Cemal; Acir, NurettinIn this study, a novel complex valued adaptive filter algorithm is proposed satisfying stability in the sense of Lyapunov. The prediction capability of the proposed algorithm is presented by using complex valued autoregressive process and wind signal in the literature. The proposed complex valued adaptive filter algorithm is compared with standard complex normalized least mean square algorithm and performed in a high performance. © 2014 IEEE.Öğe Effect of load increase and power system stabilizer on stability delay margin of a generator excitation control system(Scientific and Technological Research Council of Turkey, 2016) Sönmez, Şahin; Ayasun, SaffetThis paper studies the impact of load increase and a power system stabilizer (PSS) on the stability delaymargin of a single-machine-infinite-bus system including an automatic voltage regulator. An analytical method isproposed to determine the stability delay margin of the excitation control system. The proposed method first eliminatestranscendental terms in the characteristic equation of the excitation system without making any approximation and transforms the transcendental characteristic equation into a regular polynomial. The key result of the elimination process is that the real roots of the new polynomial correspond to the imaginary roots of the transcendental characteristic equation. With the help of the new polynomial, it is also possible to determine the delay dependency of system stability and the root tendency with respect to the time delay. Delay margins are computed for various loading conditions and PSS gains. It is observed that the delay margin generally decreases as the PSS gain and load demand increase, resulting in a less stable system.Öğe Horata (Malatya) Karstik Kaynağı'nın hidrojeoloji incelemesi(2002) Günaydın, Osman; Çetindağ, Bahattin; Fener, Mustafaİnceleme alanı Malatya il merkezinin güneyinde yer almaktadır. İnceleme alanı Paleozoyik, Mesozoyik ve Senozoyik yaşlı birimlerden oluşmaktadır. Bunlar Malatya Metamorfitleri, Gündüzbey Formasyonu, Yeşilyurt Formasyonu, Taraça ve Alüvyondur. Horata Karstik Kaynağı'nda uzun süreli debi değişimi ve iyon değişimi kontrol edilmiştir. ...
