Utjecaj nadmorske visine i starosti zatvorenog češera na klijanje sjemena crvenog bora (Pinus brutia Ten.)

This study investigated changes in the germination rate and germination percentage of seeds obtained from closed pine cones (Pinus brutia Ten.) of different ages collected at different altitudes. The seeds used in the study were obtained from closed cones (3/control, 4, 5, 6, and 7 years old) in the lower (0-200 m) and higher (800-1000 m) altitude zones of the Mersin-Anamur region in a section from the sea to the interior. The seeds germinated in the dark at a constant temperature of 20 °C for 28 days. At the end of the germination test, a two-way analysis of variance was performed on the germination percentage data on the 10th, 14th, and 28th days, and the interactions between altitude and cone age were found to be significant (p = 0.05). As a result of the significant interaction between the two groups, the mean separation test (Tukey test) showed that the highest germination rate was 89.0% in the control group, and the lowest was 77.5% in the 7-year-old cones. In the higher altitude zone, the highest germination rate was 74.0% and the lowest was 71.0%, obtained from 5- and 7-year-old seeds, respectively. In general, germination values in the lower altitude zone were higher than those in the higher altitude zone. However, the decrease in germination values from the control to the 7-year-old seeds was greater in the lower altitude zone than in the higher altitude zone. The study found that altitude was more effective than cone age on the germination rate and percentage.U ovom istraživanju analizirane su promjene u stopi klijavosti i postotku klijavosti sjemena iz zatvorenih češera Pinus brutia Ten. različite starosti, sakupljenih na različitim nadmorskim visinama. Sjeme korišteno u istraživanju dobiveno je iz zatvorenih češera (3/kontrola, 4, 5, 6 i 7 godina starosti) u nižim (0-200 m) i višim (800-1000 m) visinskim zonama Mersin- Anamurske regije rasprostranjenih od mora prema unutrašnjosti. Sjeme je klijalo u mraku pri konstantnoj temperaturi od 20 °C 28 dana. Na kraju testa klijavosti provedena je dvostruka analiza varijance o postotku klijavosti 10., 14. i 28. dana, te je utvrđeno da su interakcije između nadmorske visine i starosti češera značajne (p = 0,05). Kao rezultat značajne interakcije između dviju skupina, srednji test razdvajanja (Tukey test) pokazao je da je najveća klijavost bila 89,0% u kontrolnoj skupini, a najniža 77,5% u 7-godišnjim češerima. U zoni viših nadmorskih visina najveća klijavost iznosila je 74,0%, a najmanja 71,0%. Dobivena je iz sjemena starih 5 odnosno 7 godina. Općenito, vrijednosti klijavosti u zoni niže nadmorske visine bile su veće od onih u zoni više nadmorske visine. Međutim, smanjenje vrijednosti klijavosti od kontrolnog do 7-godišnjeg sjemena bilo je veće u zoni niže nadmorske visine nego u zoni više nadmorske visine. Studija je pokazala da je na stopu klijanja i postotak, nadmorska visina učinkovitija od starosti češera

Fitotoksičnost klopiralida vezano uz klijanje sjemena mediteranskih borova

Black pine (Pinus nigra J. F. Arnold), maritime pine (P. pinaster Aiton), Scots pine (P. sylvestris L.), and Turkish red pine (TRP, P. brutia Ten.) are ecologically and economically important conifers of the Mediterranean Basin, and in particular for Turkish forestry. They are commonly used for the regeneration and restoration of degraded ecosystems in Turkey. Weeds compete with tree seedlings for vital site elements such as soil moisture and nutrients and solar radiation, substantially reducing tree establishment and growth. Herbicides can offer the practitioner efficient and cost-effective weed control compared to other methods. Rapid herbicide seed screening allows testing of crop-safe herbicides and application rates at much lower costs in a very short time-frame when compared to lengthy field trials. Clopyralid is a systemic herbicide used to rid pine seedlings of competing vegetation. The present study examined the effect of clopyralid phytotoxicity on these pine species using a rapid herbicide seed screening test in order to compare different application rates on seed germination and to identify crop-safe rates. Clopyralid was not phytotoxic to any of the pine species at low rates (i.e., <2%, v:v); however, pine sensitivity to the herbicide increased with increasing rates, especially for rates higher than 3%. Moreover, at high rates, clopyralid reduced the germination speed. This herbicide can be used at low rates for degraded areas and nursery sites in which sowing is used as the main regeneration or restoration method. Field confirmation of the obtained results is also recommended.Crni bor (Pinus nigra J. F. Arnold), primorski bor (Pinus pinaster Aiton), obični bor (Pinus sylvestris L.), i brucijski bor (TRP, Pinus brutia Ten.) su ekološki i ekonomski važne četinjače u mediteranskom području, a posebno za tursko šumarstvo. Obično se koriste za regeneraciju i sanaciju degradiranih eko sustava u Turskoj. Korovske biljke su u kompeticiji sa sadnicama drveća jer im oduzimaju vlagu, hranjive tvari i sunčevu svjetlost, što može značajno smanjiti rast i razvoj sadnica. Herbicidi se u praksi koriste za učinkovitu i isplativu kontrolu korova jer smanjuju troškove u usporedbi s ostalim metodama njihovog suzbijanja. Brzo skeniranje herbicida za sjeme omogućuje skeniranje herbicida sigurnih za uzgoj uz znatno niže troškove i u vrlo kratkom vremenu u usporedbi s dugotrajnim pokusima na terenu. Klopiralid je sustavni herbicid koji se koristi za zaštitu sadnica istraživanih borova od konkurentne vegetacije. U ovom istraživanju, fitotoksičnost klopiralida je istražena uz pomoć testa za brzo skeniranje herbicida za sjeme kako bi se usporedila njegova primjena kod klijanja sjemena te radi utvrđivanja sigurne doze. Klopiralid nije bio fitotoksičan niti za jednu vrstu bora pri niskim dozama (npr., <2%, v:v), ali se osjetljivost borova na herbicid povećala s većom dozom, posebno ako su doze bile veće od 3 %. Klopiralid je smanjio brzinu klijanja u visokim dozama. Ovaj herbicid se može koristiti u manjim dozama za degradirana i rasadnička mjesta na kojima se koristi sjetva sjemena kao glavna metoda sanacije i regeneracije sastojina. Preporučena je također i potvrda rezultata s terena

EVALUATION OF IMPACT TO PISA SUCCESS OF SCHOOL-BASED MANAGEMENT POLICIES

In this study, countries with the highest levels of achievement according to math and science scores in the PISA exams and countries with the lowest levels of achievement were compared in terms of school-based management policy indicators in education. This research is a quantitative research method. The research is in statistical scanning model. Data are taken directly from EUROSTAT, OECD and PISA database. The educational systems of the countries with the highest scores in the PISA exams and the countries with the lowest scores were compared. It is seen that local governments have more funding for schools, schools have the authority to determine their own teachers, schools have the authority to determine the textbooks, students have the authority to evaluate student achievement and the school budget, and these rates are above the OECD average. In high score countries inter-school disadvantage was below the OECD average. In low score countries inter-school disadvantage was above the OECD average.   Article visualizations

An Alexandrov Topology for Maximal Cohen-Macaulay Modules

Using the theory of cohomology annihilators, we define a family of topologies on the set of isomorphism classes of maximal Cohen-Macaulay modules over a Gorenstein ring. We study compactness of these topologies.Comment: 22 page

The effect of heating process on Turkish red pine (Pinus brutia Ten.) seeds

Bu çalışmada, Anamur ve Mersin yörelerinden seçilen 2 kesitteki 4’er yükselti kuşağından (0-400 m, 400-800 m, 800-1200 m ve ≥1200 m) toplanan kızılçam (Pinus brutia Ten.) tohumlarına ısıtma işlemi (1, 3, 5 ve 7 dakika) uygulanmış ve bu tohumların çimlenme özelliklerindeki değişim irdelenmiştir. Araştırmada, ısıtma işlemi uygulanan tohumların hangi sıcaklıkta çimlendirileceğini tespit etmek amacıyla 15, 20 ve 25oC ön çimlendirme testleri yapılmış ve sırasıyla %44,2, %68,1 ve %52,0 çimlenme yüzdeleri elde edilmiştir. Bu çimlendirmelerde en yüksek çimlenmeler her iki kesitte ve bütün yükselti kuşaklarında 20oC’de (%68,1) olmuş ve ısıtma işlemi uygulanan tohumlarda bu sıcaklıkta çimlendirilmiştir. Yapılan çimlendirme denemelerine göre, yükseltinin artmasıyla çimlenme performansları düşmüştür. Isıtılan tohumlarda çimlenme yüzdeleri, genel olarak alt yükselti kuşağından üst yükselti kuşağına doğru azalmıştır. 150oC’de ısıtılan tüm tohumlarda 1 dakika ısıtma süresinde (%62,9) kontrole (%66,4) yakın çimlenmeler hatta bazı yükselti kuşaklarında kontrolden daha fazla çimlenme elde edilmiştir. 3 dakika ısıtma süresindeki (%33,9) çimlenmelerde önemli oranda düşüşler olmuş ve 5 dakikalık ısıtma süresinde (%3,3) ise az miktarlarda çimlenme gözlenmiştir. 7 dakika ısıtma süresinde, bütün yükselti kuşaklarında tohumlar tamamen canlılığını kaybetmiş ve hiç çimlenme (%0,0) olmamıştır.In this study, Turkish red pine (Pinus brutia Ten.) seeds were collected from four altitudinal belts (0-400 m, 400-800 m, 800-1200 m and ≥1200 m) on 2 transects in Anamur and Mersin regions. Heating process (1, 3, 5 and 7 minutes) was applied to seedlings and changes in germination characteristics were investigated. In order to determine germination temperatures of seeds, pre-germination tests were done at 15, 20, 25oC and germination percentages of these temperatures were 44.2%, 68.1% and 52.0% respectively. The highest germination rates were observed in both transects on every altitudinal belt at a temperature of 20ºC (68.1%). According to the germination tests, the germination performances were decreased with increasing altitude. Germination ratios of the heated seeds were decreased from lower to higher altitudinal belts. The germination rates of the seeds which were heated at 150oC for 1 minute (62.9%) were close to the control (66.4%). In addition, even higher germinations were obtained at some altitudinal belts. However, germinations at the heating for 3 minutes were considerably decreased (33.9%) and for 5 minutes few germinations occured. Vitality of seeds were lost and no germinations were seen (0.0%) at the heating for 7 minutes.Publisher's Versio

Morfología y tipificación de Szovitsia callicarpa (Apiaceae)

The poorly known monotypic genus Szovitsia Fisch. & C.A.Mey, in the Apiaceae family, is here revised. Szovitsia callicarpa Fisch. & C.A.Mey. is an annual herb with a restricted distribution in the Caucasus region and adjacent areas of northwestern Iran and northeastern Turkey. The genus is unusual within the family because of the transverse plicae covering its fruits. In this study, morphological, micromorphological, and anatomical characters of S. callicarpa are reviewed. In addition, a previous lectotypification of the name S. callicarpa is discussed and amended.Se revisa Szovitsia Fisch. & C.A.Mey, un género monotípico y poco conocido en la familia de las Apiaceae. Szovitsia callicarpa Fisch. & C.A.Mey. es una hierba anual con una distribución restringida a la región del Cáucaso y áreas adyacentes del noroeste de Irán y noreste de Turquía. El género es inusual dentro de la familia debido a los pliegues transversales que cubren sus frutos. En este estudio se revisan los caracteres morfológicos, micromorfológicos y anatómicos de esta especie. También se discute y modifica una lectotipificación previa del nombre S. callicarpa

The Effect of Family Attitudes and Preparation of High School Entrance Exam on Habitual Physical Activity in Children

AbstractPhysical activity level (PAL) is an important factor to promote and maintain a healthy lifestyle along the whole life cycle. The children and adolescent period is the critical time to acquire positive lifestyle habits. The purpose of this study was to investigate the effect of both high school entrance exam (HSEE) and parental behaviors on habitual PAL of students during the preparation of this exam. Totally 319 Elementary School students (154 girls, 165 boys) between ages of 11-13 were selected randomly for this study. PAL of students were evaluated by using the Beacke Physical Activity Questionnaires. There were a no significant differences between attendance and non attendance to extra courses for HSEE in terms of word activity (WA), sport activity (SA), and leisure activity (LA) scores (p<.05) among the students. It was shown that regular physical activity attendance of mothers plaid a significant role in LA scores (p≤.03) among the students. However, WA, and SA scores of students were not affected from their mother's habitual activities (p<.05). On the other hand, there were significant differences in WA, and SA according to father's regular physical activity attendance (p≤.01).As a conclusion, parental habitual physical activity level played an important role in high score of student's LA. It is recommended to monitor and promote parental physical activity

Honey Plants of Düzce University Ornamental and Medicinal Plants Botanical Garden

In this study, melliferous plants that the honey bee (Apis mellifera L.) can benefit from among the taxa planted in Düzce University Ornamental and Medicinal Plants Botanical Garden, are presented. Among the 451 taxa planted in the botanical garden, those with these characteristics were determined by reviewing studies on the subject. Of the 165 taxa (36.58%) included in the honey plant class; 119 contain both nectar and pollen, 25 contain pollen, 13 contain nectar, 4 contain both pollen and insect secretion (IS) or sweet sap (SS), 2 contain pollen, nectar and IS or SS, 1 contain both nectar and SS, 1 contain only IS. In order to prevent the decrease in pollinator and pollinator insects, whose numbers are decreasing due to global climate change, a "Bee and Insect Hotel" was placed in the botanical garden. For this reason, the majority of the plants selected for planting were chosen from taxa with honey plant properties. The main purpose here is both to pollinate the plants in the botanical garden and to show and explain the effects of insect species on pollination through nature education

Cesium Removal From Aqueous Solution Using Nanocomposite Material

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2015Radyonüklid içeren radyoaktif atıklar en tehlikeli çevresel atık olarak düşünülürler. İçerdikleri radyonüklidlerin uzun yarı ömürlü, yüksek fizyon ürünleri olması, atmosferde çok hızlı bir şekilde hareket edebilmesi ve canlı metabolizmasına çok kolay bir şekilde katılması bu radyonüklidleri çok tehlikeli olmasının başlıca nedenlerindendir [1]. Radyoaktif atıklar nükleer güç santralleri işletilmesi sırasında ve bunların kazası sebebiyle, radyoizotop üretim tesislerinden, nükleer yakıt geri işlenmesinden ve üniversitelerin radyokimya laboratuvarlarından meydana gelirler. Bu radyonüklidler arasında en yaygın olanı Cs-137 ve Sr-90 radyoizotoplarıdır. Bu sebeple bu iki radyonüklidin sulu radyoaktif atık çözeltilerinden uzaklaştırılması çok önem kazanmıştır[2]. Günümüze kadar, sulu radyoaktif atıklardan Cs (I) ve Sr (II) iyonlarının uzaklaştırılmasında birçok metod uygulanmıştır. Bunların en önemlileri iyon değiştirme, çöktürme, adsorpsiyon, çözücü ekstraksiyon, elektrokimyasal ve membran prosesleridir. Adsorpsiyon prosesi diğer yöntemlere göre düşük maliyeti, termal kararlılığı, iyonlaştırıcı radyasyona karşı dirençliliği ve atığın son formuyla uyumlu olması nedenleri ile en çok tercih edilenidir[3]. Son zamanlarda, birkaç düşük maliyetli biyosorbentler ağır metallerin uzaklaştırılması araştırmalarında kullanılmıştır. Bu çalışmada, pirinç kabuğu-biyosorbent-tarımsal atık değerlendirilerek bir kompozit malzeme hazırlandı. Yenilikçi bir teknoloji olan manyetik malzemeler; atık sulardaki koagülasyonu hızlandırmada, sütten radyonüklidlerin uzaklaştırılmasında, organik boyaların adsorbsiyonunda ve petrol tanker kazaları sonucu denize dökülen petrolün uzaklaştırılmasında kullanılmaktadır ve son yılların en ilgi çeken uygulamaları arasındadır. Manyetik kompozitler şu özellikleri göstermektedir: (i) Kil veya aktif karbon gibi adsorbentlerin adsorpsiyon özelliklerini ve Hematit’in manyetik özelliğini birleştirirler, (ii) farklı tipteki kontaminantların örneğin metal veya organik türlerin sudan uzaklaştırılmasında kullanılabilir, (iii)basit bir manyetik ayırma prosesi ile ortamdan kolaylıkla uzaklaştırılabilirler[4]. Nanokompozit malzemelerin genellikle yüksek performanslı santrifüj işlemleri ile ayrılması gerekir. Bu nanokompozitlerde karşılaşılan en önemli zorluktur çünkü hem zaman alıcıdır hem de pahalıdır ama nanokompozitleri manyetik ayırma ile ortamdan uzaklaştırılması kolay, etkili ve basittir. Son zamanlardaki literatür çalışmaları incelendiğinde Cs ve Sr adsorpsiyonunda bir çok adsorbent ve teknik kullanılmıştır. Bu çalışmada tarımsal bir atık olan pirinç kabuğundan elde edilen kül, hematit (Fe3O4) ile birleştirilerek nanokompozit bir malzeme sentezlendi ve sezyum ve stronsiyum adsorpsiyonunda kullanıldı. Literatürde pirinç kabuğu sulu radyoaktif atıklardan Cs uzaklaştırılmasında kullanılmış ancak külden hazırlanan herhangi bir kompozit malzeme sözü edilen analitlerin uzaklaştırılmasında kullanılmamıştır. Çalkalama (batch) yöntemi kullanılarak pH, sıcaklık, adsorbent miktarı, çalkalama süresi ve çalkalama hızı gibi adsorpsiyon parametrelerin adsorpsiyon üzerine etkileri araştırıldı. Optimum parametreler belirlendikten sonra Sr varlığındaki Cs adsorpsiyonun kapasitesi belirlendi. Süzüntüde kalan Cs ve Sr iyonlarının konsantrasyonları hava/asetilen alevinin kullanıldığı alevli atomik absorpsiyon spektrofotometresinde tayin edildi. SEM-EDX analizinden sonra, RHA-Fe3O4 adsorbentin partikül şeklinin düzenli olmadığı sonucuna varıldı. RHA- Fe3O4 oluşturmak üzere pirinç kabuğu külünün Fe3O4 ile muamelesi sonrası yüzey alanı pirinç kabuğunun yüzey alanının neredeyse iki katı kadar daha artmıştır. RHA-Fe3O4 yüzey alanı 156,34 m2/g’dır. XRF analizinden, RHA-Fe3O4 adsorbentinin Fe, Si, S, Sb ve Sn elementlerinden oluştuğu anlaşıldı ve sırasıyla yüzde miktarları 71,50, 18,93, 9,42, 0,08 ve 0,06 olarak belirlendi. Manyetik nanokompozit adsorbenti sentezlemek için önce pirinç kabuğu çift distile sui le toprak ve tozdan arındırılmak için yıkandı ve 76 saat boyunca 0.1 M HCl çözeltisinde saklandı sonar klorür iyonlarını uzaklaştırmak için üç kez çift distile sui le yıkandı ve 105 oC’de 2 saat kurutuldu. Kurutulmuş pirinç kabuğu kroze içerisine alındı ve 800 oC’de 5 saat fırında yakıldı. Bu işlemlerden sonar, 10 mL 2M FeSO4.7H2O ve 40 mL 1 M FeCl3 çözeltileri behere ilave edildi, 70 oC’ye kadar ısıtıldı ve 3,3 g pirinç kabuğu külü karıştırılarak behere ilave edildi. Hematit’i çöktürmek için 100 mL 5M NaOH çözelitisi damla damla ilave edildi. Çökelti çift distile sui le yıkandı ve mavi bantlı süzgeç kağıdı ile süzüldü. Sentezlenen siyah renkli manyetik kompozit 80 oC’de 2 saat fırında kurutuldu. pH, başlangıç konsantrasyonu, çalkalama süresi, adsorbent kütlesi ve sıcaklık gibi çeşitli değişkenlerin etkisi araştırıldı. Optimum parameter olarak pH:6, başlangıç konsantrasyonu 30 ppm, çalkalama süresi 30 dakika, adsorbent kütlesi 0,01 g ve sıcaklık 25 oC olarak belirlendi. Maksimum adsorpsiyon kapasitesi 28,82 mg Cs/g olarak bulundu. Denge adsorpsiyonu verileri Langmuir ve Freundlich izoterm modelleriyle açıklandı ve sonuçlar korrelasyon katsayısı 0,943 olan Langmuir modeline daha iyi uydu.Removal of pollutants from industrial wastewater has become one of the most important issues recently for the increase in industrial activities, especially for heavy metals and radionuclides.Radioactive wastes containing radionuclides have been considered as the most hazardous environmnetal pollutants. In recent years, with the development of nuclear technology and industry, much radioactive waste is released into water, which leads to a direct threat to human health. The main factors why they are so hazardous are containing long half-life radionuclides, high fission yields, high mobility of radionuclides in the atmosphere and easiliy joining the metabolism of living beings. Radioactive wastes are generated from nuclear power plants operation and their accidents, radioisotop production laboratories, nuclear fuel recyciling processes and univercities radiochemistry laboratories. Among the most common radionuclides are Cs-137 and Sr-60. Because of this, removal of these two radionuclides is very important.  Nowadays, many different methods have been applied to remove Cs(+1) and Sr (+2) ions from aquaeous radioactive wastes. Most important methods are ion exchange, precipitation, adsorption, solvent extraction elctrochemical and membran processes. Among them, adsorption is most preferred method because of low cost, thermal stability, resistance toward ionization radiation and compatible with the final form of waste. The role of dead biomasses in the removal of heavy metal toxic ions received an increased attention during recent past as due to its fairly good exchange capacity, large abundance, and also cost effectiveness. However, scanty reports appeared for the possible application of dead biomasses in the removal of radiotoxic ions particularly the radiocesium and radiostrontium. Recently, several low cost biosorbents have been used to remove heavy metals in investigations. Biosorbent used in this study is rice husk which is a agricultural residue. An innovative technology that has gained attention is the use of magnetic materials to solve environmental problems, such as accelerating the coagulation of sewage, removing radionuclides from milk, adsorption of organic dyes and oil spill remediation. The advance in magnetic nanoparticles (MNP) has made it possible to utilize several advantages of using nanosized sorbent without typical difficulty associated with separation of nanoparticles from solution. MNP can be easily separated from the treated solution by simple application of either a permanent or electro magnet. Their uses have been proven very successful, particularly in the field of bio-nanotechnology, where MNP functionalized with various functional groups have been used in the isolation and purifications of DNAs, proteins, or drug delivery. Magnetic nanoparticles have also been used for treatment and recovery of several heavy metals and radioactive nuclides such as uranium and plutonium. These magnetic materials show the following features: (i) they combine the adsorption properties of adsorbent such as activated carbon or clay with the magnetic properties of iron oxides. (ii) they can be used to remove different types of contaminants for example metals or organics from water, (iii) they can be removed from the medium by a simple magnetic seperation process. Nanocomposite particules usually need to be seperated by high performance centrifugations, this is the most important challenge with nanocomposites because this process is time consuming and expensive but using magnetic separation to seperate nanocomposites from medium is easy, fast, efficient and simple. Recently, when the literature studies were investigated, many type of adsorbent and technique were used to remove Cs and Sr from aquaeous waste solutions. In this study, an agricultural residue rice husk was heated to form its ash then it combined with iron oxide to synthesis nonocomposite material which was used to remove Cs and Sr from aquaeus waste solutions. Using batch method, adsorption parameters such as pH, temperature, adsorbent mass, contact time and shaking rate and initial Cs concentration were determined. After determination of optimum parameters, in existance of Sr, Cs adsorption capacity has been determined. Cs and Sr ions concentrations in supernatant were determined using flame atomic absorption spectrometer equipped with hallow cathode lamp of Cs and Sr as a radiation source and air/acetylene burner for atomization. After SEM-EDX analysis, we concluded that particul shape of RHA-Fe3O4 adsorbent is not regular. The surface area is almost twice larger then Rice Husk’s surface area after rice husk was treated with Fe3O4 to compose RHA- Fe3O4. The surface area of RHA- Fe2O3 is 156.34 m2/g. From XRF analysis, it can be seen that RHA- Fe3O4 is composed of Fe, Si, S, Sb and Sn elements. Their percentage amounts are 71.50, 18.93, 9.42, 0.08 ve 0.06 respectively. To synthesize magnetic nanoparticle adsorbent, after rice husk washed with double-distilled water to remove dusk and soil, it stored in 0.1 M HCl solution for 76 hours then washed three times to remove chloride ions and dried at 105 oC for 2 hours. Dried rice husk was burn in a crucible at 800 oC for 5 hours in an oven to obtain rice husk ash. After these process, 10 mL 2M FeSO4.7H2O and 40 mL 1M FeCl3 solution were added to 400 mL beaker, heated up to 70 oC then 3.3 g rice husk ash was added into this solution while stirring. To precipitate iron oxide, 100 mL 5M NaOH solution was added drop by drop. To understand that the composite is magnetic or not, an electro magnet was brought closer to beaker and composite in beaker was coagulated on the electro magnet side of the beaker. Precipitate was washed distilled-deionized water and filtered with blue banded filter paper. Synthesized black coloured magnetic composite was dried in an oven at 80 oC for 2 hours. Dried magnetic composite was grinded into powder form.  The effect of different variables such as pH, initial concentration, shaking time, adsorbent mass and temperature was studied. Optimum parameters we concluded  as pH:6, 30 ppm initial concentration, 30 minutes shaking time, 0.010 g adsorbent mass and 25oC temperature. Maximum adsorption capacity was found 28,82 mg Cs/g RHA-Fe3O4. The equilibrium sorption data were described by the Langmuir and Freundlich isotherm models and the results could fit more with Langmuir model with correlation coefficient 0.943.  From literature studies, it can be seen that cesium adsorption capacities change between 0.011 mg Cs/g adsorbent and 1965 mg Cs/g adsorbent. Magnetic nanocomposite rice husk ash shows higher adsorption capacity from polyacrylonitrile-zeolite nanocomposite, hexacyanoferrate-polymer composite, wallnut-shell, bentonite supported polymer and magnetic zeolite nanocomposite adsorbent.Yüksek LisansM.Sc

Refah MKYK üyesi Ceylan rest çekti "Sarıklıya kimse dokunamaz"

Donated by Klaus KreiserReprinted from : Yeniyüzyıl Gazetesi, Yıl: 3, Sayı: 824, 18 Mart 1997