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Like all biofluid-contacting medical devices, intranasal splints are highly prone to bacterial adhesion and clot formation. Despite their widespread use and the numerous complications associated with infected splints, limited success has been achieved in advancing their safety and surface biocompatibility, and, to date, no surface-coating strategy has been proposed to simultaneously enhance the antithrombogenicity and bacterial repellency of intranasal splints. Herein, we report an efficient, highly stable lubricant-infused coating for intranasal splints to render their surfaces antithrombogenic and repellent toward bacterial cells. Lubricant-infused intranasal splints were prepared by creating superhydrophobic polysiloxane nanofilament (PSnF) coatings using surface-initiated polymerization of n-propyltrichlorosilane (n-PTCS) and further infiltrating them with a silicone oil lubricant. Compared with commercially available intranasal splints, lubricant-infused, PSnF-coated splints significantly attenuated plasma and blood clot formation and prevented bacterial adhesion and biofilm formation for up to 7 days, the typical duration for which intranasal splints are kept. We further demonstrated that the performance of our engineered biointerface is independent of the underlying substrate and could be used to enhance the hemocompatibility and repellency properties of other medical implants such as medical-grade catheters.

A superamphiphobic surface having both water and oil repellence was prepared by applying a solvent-free surface coating method using liquid-CO2 in the scope of "green chemistry". Poly(perfluoroalkyl ethyl acrylate) homo- polymer was synthesized by a free radical polymerization in supercritical CO2 medium. This polymer was dissolved in liquid-CO2 containing hydrophilic nanosilica particles in a stirred stainless steel reactor at room temperature under a low CO2 pressure. The polymer/nanosilica dispersion was used to coat glass slides located horizontally in a stainless steel tube by using the "free meniscus coating" method. A series of superamphiphobic coatings were formed under different coating conditions with the variation of polymer/nanosilica concentrations, the types of nanosilica powders, system pressures, and degassing flow rates. The highest apparent water contact angle was 173 degrees and the hexadecane contact angle was 169 degrees on these superamphiphobic hybrid coatings with roll-off angles that were

Although many factors are considered to improve the properties of graphene filaments, there is no report in the existing Literature on the effect of the temperature of the coagulation bath to the mechanical properties of graphene oxide filaments obtained in the wet-spinning process and also to the mechanical and electrical properties of the resulting graphene filaments after reduction. In this study, the effect of the temperature of the isopropanol coagulation bath during wet-spinning of graphene filaments on their final properties after formation was investigated and it was found that the decrease of the coagulation bath temperature resulted in more compact filaments having better mechanical properties for both graphene oxide and corresponding reduced graphene filaments. The best tensile strength and Young's modulus values were obtained in isopropanol coagulation bath which was kept at 15 degrees C. On the other hand, the types of the chemical reduction agents which can provide better electrical conductivity to graphene filaments after reduction were also investigated and it was determined that the use of hydriodic acid/acetic acid mixture resulted in graphene filaments having the best electrical conductivity (1.28 x 10(4) S m(-1)) and also tensile strength (234 +/- 26 MPa) values. The addition of acetic acid into hydriodic acid increased the tensile strength 26% when compared with the plain HI treatment. Both electrical conductivity and tensile strength results were higher than most of the previously reported values of the wet-spun neat graphene filaments in the Literature.

Three different characterization tests namely, ice adhesion strength, drop freezing time and a newly developed ice accretion method were applied to surfaces which were commonly used in anti-icing research such as aluminum, stainless steel, copper, styrene butadiene rubber, polypropylene and polytetrafluoroethylene in order to investigate the effect of their water wettability and surface free energies on their anti-icing performances. It was found that ice adhesion strengths increased and drop freezing times decreased with the increase of the total surface free energies and decrease of the water contact angles on these surfaces similar to previously published reports however, no direct relationship was found between the ice accretion results and solid wettability, surface free energies and the reasons were discussed in terms of heterogeneous nucleation mechanisms. (C) 2016 Elsevier B.V. All rights reserved.

Bu çalışmada yüzeyleri üç farklı bileşimdeki hidrofob emülsiyonla kaplanan şeftaliler oda şartlarında muhafaza edilmişlerdir. Kaplanmış şeftali örnekleriyle kaplanmamış referans örneklerde muhafaza sırasında meydana gelen ağırlık kaybı, titre edilebilir asitlik, askorbik asit, suda çözünebilen kuru madde miktarı, pH ve duyusal özelliklerindeki (görünüş, renk, doku, tad-aroma) değişmeler periyodik olarak saptanmıştır. Balmumu-koko yağı emülsiyonu ile kaplı şeftalilerdeki ağırlık kaybı ile kimyasal yapıdaki bozulma hızlarının, kaplanmamış referans örneklere göre daha az olduğu saptanmıştır. Kaplanmamış örneklerin duyusal kaliteleri 10 gün sonunda kabul edilemez duruma gelirken, balmumu-koko yağı emülsiyonuyla kaplı örneklerde bu sürenin 14 gün olduğu gözlenmiştir. Bu kaplamanın su buharı ve oksijen transferini azaltarak, şeftalinin solunum hızını düşürdüğü, böylece bozulma süresini geciktirdiği anlaşılmıştır.

The instability of implants after placement inside the body is one of the main obstacles to clinically succeed in periodontal and orthopedic applications. Adherence of fibroblasts instead of osteoblasts to implant surfaces usually results in formation of scar tissue and loss of the implant. Thus, selective bioadhesivity of osteoblasts is a desired characteristic for implant materials. In this study, we developed osteoselective and biofriendly polymeric thin films fabricated with a simple phase separation method using either homopolymers or various blends of homopolymers and copolymers. As adhesive and proliferative features of cells are highly dependent on the physicochemical properties of the surfaces, substrates with distinct chemical heterogeneity, wettability, and surface topography were developed and assessed for their osteoselective characteristics. Surface characterizations of the fabricated polymer thin films were performed with optical microscopy and SEM, their wettabilities were determined by contact angle measurements, and their surface roughness was measured by profilometry. Long-term adhesion behaviors of cells to polymer thin films were determined by F-actin staining of Saos-2 osteoblasts, and human gingival fibroblasts, HGFs, and their morphologies were observed by SEM imaging. The biocompatibility of the surfaces was also examined through cell viability assay. Our results showed that heterogeneous polypropylene polyethylene/polystyrene surfaces can govern Saos-2 and HGF attachment and organization. Selective adhesion of Saos-2 osteoblasts and inhibited adhesion of HGF cells were achieved on micro-structured and hydrophobic surfaces. This work paves the way for better control of cellular behaviors for adjustment of cell material interactions. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 154-161, 2015.

Superhydrophobic and oleophobic rubbery coatings were prepared by spraying perfluoroalkyl ethyl acrylate (Zonyl TA-N) grafted styrene butadiene rubber (SBR) solution in toluene after addition of hydrophilic and hydrophobic fumed silica powders onto glass. Grafting onto SBR has been performed by free radical copolymerization in toluene using different Zonyl TA-N feed compositions. Molecular weights of the graft copolymers were determined by GPC and intrinsic viscosity measurements. Thin films of Zonyl TA-N grafted SBR copolymers were prepared by dip coating glass slides into toluene solutions of SBR-g-Zonyl TA-N with varying fluoromonomer contents and their surface free energies were determined by contact angle measurements. The increase in Zonyl TA-N content resulted in a considerable decrease of the total surface free energy of the grafted SBR film. Later, superhydrophobic and oleophobic surfaces were prepared by adding hydrophilic and hydrophobic fumed silica powders into graft copolymer solutions and spraying onto glass. The effect of the Zonyl TA-N content in the graft copolymer, type of silica and its weight concentration in the solution on the water and hexadecane contact angle values, on the surface morphology and mechanical durability of the coatings were investigated. The highest water contact angle of the SBR-g-Zonyl TA-N/SiO2 hybrid coatings was determined to be 162 degrees and hexadecane contact angle 147 degrees after adjusting the silica type, solids content and fluoroacrylate/SBR composition of the graft copolymer spray solution. (C) 2015 Elsevier B.V. All rights reserved.

Superhydrophobic and oleophobic rough copolymer surfaces containing micro- and nano-hierarchical ball-like islands having diameters between 100 nm and 7 mu m were formed using styrene-perfluoromethacrylate random copolymers which were dip-coated on glass slides from THF and MEK mixture containing methanol as nonsolvent. These copolymers were synthesized in a CO2-expanded monomer medium at 250 bar pressure and 80 degrees C. The sizes of the micro-islands can be controlled by varying the copolymer composition; and the degree of phase separation by adjusting the solvent/non-solvent ratio. Flat and lotus-like hierarchical surfaces of the copolymers were characterized using contact angle measurements and SEM. The increase in the perfluoromethacrylate content of the flat copolymers resulted in a decrease of the total surface free energy of the flat copolymer surfaces from 18.3 down to 14.2 mJ/m(2). The increase in the methanol non-solvent fraction resulted in decrease of the micro-island diameter from 7 mu m down to 100 nm and the water contact angle increased from 117 degrees up to 160 degrees and hexadecane from 65 degrees up to 90 degrees. (C) 2013 Elsevier B.V. All rights reserved.

Statistical copolymers of perfluoroalkyl ethyl methacrylate (Zonyl-TM) and styrene (S) were synthesized in CO2-expanded monomer medium at a low initial pressure of 25 MPa. Different Zonyl-TM/S feed ratios were used during copolymerizations, and it was determined that the increase in the Zonyl-TM content and decrease of the CO2 amount in the comonomer feed resulted in a decrease of the molecular weights of copolymers due to earlier precipitation of copolymers giving shorter chains. The cloudy CO2-expanded liquid monomer phase was found to be the main loci of copolymerization. In addition, the increase in the Zonyl-TM feed ratio resulted in an increase in the critical degree of the polymerization time (J (crit)) as the time when the copolymer chains start to precipitate. The higher the Zonyl-TM content used in the feed, the higher the J (crit) time and the lower the weight-average molecular weight (M (w)) of the copolymer obtained. Thermal analysis results of the copolymer indicated that the copolymers are stable up to 387-403 A degrees C.

In this study, we investigated the factors affecting the lifetime of liquid marbles placed on a glass surface and floating on water It was found that the particle size, surface free energy and hydrophobicity of the encapsulating microparticles determine the effective surface tension and lifetime of a liquid marble floating on water We formed liquid marbles using ultra-hydrophobic poly(perfluoroalkyl ethyl acrylate) powder with three different particle sizes (8 +/- 1, 20 +/- 2 and 60 +/- 5 mu m) and polytetrafluoroethylene powder (7 +/- 2 mu m). It was found that both the effective surface tension and lifetime of a floating liquid marble increased considerably with the decrease in the particle size of the ultra-hydrophobic poly(perfluoroalkyl ethyl acrylate) powder We also determined that a floating liquid marble had a longer lifetime if the water contact angle of the polymer powder was high and its surface free energy was low by comparing the results of two different powders having very close average particle sizes but different hydrophobicities.

A new statistical terpolymer containing perfluoroethyl alkyl methacrylate (Zonyl-TM), methyl methacrylate and butyl acrylate, poly(Zonyl-TM-ran-MMA-ran-BA) was synthesized in supercritical carbon dioxide at 200 bar and 80 degrees C using AIBN as an initiator by heterogeneous free radical copolymerization. Nanofibers of this terpolymer were produced by electrospinning from its DMF solution. The structural and thermal properties of terpolymers and electrospun poly(Zonyl-TM-MMA-BA) nanofibers were analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and differential scanning calorimetry. Nanofiber morphology was investigated by scanning electron microscopy. Electrospun nanofiber layer was found to be superhydrophobic with a water contact angle of 172 +/- 1 degrees and highly oleophobic with hexadecane, glycerol and ethylene glycol contact angles of 70 perpendicular to 1 degrees, 167 perpendicular to 1 degrees and 163 perpendicular to 1 degrees respectively. The change of the contact angle results on the electrospun fiber layer and flat terpolymer surfaces by varying feed monomer composition were compared and discussed in the text. (C) 2012 Elsevier B.V. All rights reserved.

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Poly( methyl methacrylate-ran-perfluoroalkyl ethyl methacrylate) copolymers having varying perfluoralkyl ethyl methacrylate ester (Zonyl-TM) contents were synthesized in supercritical CO2. Complete amorphous structures of the copolymers were verified by XRD. Young's modulus (Y-mod) of the copolymers was decreased linearly from 1.57 to 1.08 GPa and T-g values from 102 to 77 C with the increase of Zonyl-TM content. A linear relationship between the Y-mod and the T, values of the copolymer was also found. The increase of the large branched pendant groups resulted in the increase of the free volume and a corresponding decrease in Ymod and T-g of the copolymers. A good fit was found when the Schneider equation was used. Negative deviation from the Gordon-Taylor equation was observed when Zonyl-TM content was lower than 14% due to rapid increase in free volume and then a positive deviation was found due to the dipole-dipole interactions between the methyl ester and fluoroalkyl ester groups. (C) 2011 Elsevier B.V. All rights reserved.

We analyzed the long-term results of trabeculectomy operation in 100 eyes of 80 primary open angle glaucoma, patients followed up one to five years. Complete success was achieved 78 of cases (% 78). Reduce of intraocular pressure closely related to the presence of a filtering bleb. The main complication was the late appearance of lens opacities, although these seemed less frequent than the other antiglaucoma operations.

Follow-up Results in Ocular Hypertensive PatientsOcular hypertension, a relatively common and benign condition in patients over 40 years, is characterised by an intraocular pressure of 21 mmHg or higher, which accompanied by normal visual fields and optic discs. This article presented results of a 4 - year follow-up of 18 ocular hypertensive cases and emphasized that only one patient developed glaucomatous visual field loss during this period.Optic disc angiography seems to be a prognostic method capable of determination and initiation of therapy for the ocular hypertensive, who would develop glaucomatous transformaton.

v'The value of diagnostic methods in AION has been discussed. It seems that Erythrocyte se¬dimentation rate, visual field testing, Fundus Flourescein Angiography are practical and val¬uable methods in diagnosis and follow up of response to treatment. The use of Corticoster¬oids and glaucoma drugs in the treatment of AION has been discussed.✓Anterior iskemik optik nöropati (AİON) orta yaş üzeri popülasyonda önemli bir körlük ne¬denidir. AION nin patogenezinin anlaşılmasında son yıllarda önemli ilerlemeler kaydedil-miştir. Çalışmada, AİON nin etyoloji ve patogenezi yeri literatür bulguları ışığında tartışıldı.

Yer no:66 Demirbaş no: 38

ÖZET Sentetik pölimerik numb rani ar r birbirinden ayırdıkları ortamlar arasındaki gaz, sıvı, kati, iyon, ısı, ışık, radyoaktivite taşınmasını düzenleyen, kalınlıkları eni ve boylarına oranla çok düşük olan yüzeylerdir. Pölimerik membranların kimyasal ve makromoleküler yapıları bu membranların özelliklerini etkilemekte ve buna bağlı olarak da kullanıldığı alanları belirlemektedir. Membranların en belirgin işlevi seçimli geçirgenlik özelliği göstermeleridir. Bu çalışmanın amacı, sentetik pölimerik membranlarda, membranın kimyasal ve makromoleküler yapısının geçirgenlik özelliklerine etkisinin incelenmesidir. Bu çalışma kapsamında, tıpta kullanılan membranların karakterizasyonu için gerekli oksijen geçirgenliği ve endüstride kullanılan iyon değiştirici membranların karakter izasyonu için gerekli iyon geçirgenliği incelenecek özellikler olarak seçilmiştir. Çalışmanın birinci bölümünde, yüksek oksijen geçirgenliğine sahip, tıp alanında kullanılabilecek membran yapımına el verişli olan silikon monomerleri çıkış maddesi olarak alınmış tır. Bu tür bileşikler, Rj_ - Si - (OR2)3, genel formülü ile gösterilebilir. Bunada R1 vinil veya metakriloksipropil gibi doymamış bir fonksiyonlu grubu, R. ise metil veya etil gibi doymuş bir grubu belirtir., Bunlara örnek olarak alınan Y-metakriloksipropil trimetoksisilan ve vinil- trietoksisilan gibi bileşiklerdeki doymuş alkoksi grupların transesterifikasyon reaksiyonuna sokulup, dallanmış alkoller, yüksek monohidrik alkoller, eter alkoller, polihidrik alkoller, a-hidroksi asitlerle 7er değiştirilmesiyle, yeni monomerler üretilmiştir. Bu siloksan monomerlerin, metakrilik asitIV esteri monomerlerle kopo iimer izasyonundan membranlar hazırlan mıştır. Elde edilen kopolimer membranların oksijen geçirgenliği, kritik yüzey gerilimleri,, protein abborpsiyon yeteneği ölçülerek tıp uygulamalarındaki kullanılabilirliği araştırılmış tır. Tıpta kullanılan polimer membranların `çözünmüş oksijen geçirgeni iğ i kat sayısı` ölçüsünde kullanılan polarografik yön temle tam sağlıklı ölçüde yapılamamaktadır. Bunun nedeni kullanılan küçük ve karıştırmasız hücrelerde membran yüzeyinde bir sınır filmi oluşması, bunun da oksijen geçirgenliğini etkilemesidir, ayrıca hücre elektrodları zaman zaman polarize olmak` ta ölçüm esnasında elektro kimyasal yan reaksiyonlar oluşmaktadır, ölçümleri daha sağlıklı hale getirmek için cihaz sürekli kalibre edilmektedir, bu da zaman gerektirmektedir. Bu çalışma kapsamında, `çözünmüş oksijen geçirgenliği katsayısı` ölçümün de oluşan hataların önüne geçen ve ölçüm süresini kısaltan kolorimetrik bir yöntem de. geliştirilmiştir. Çalışmanın ikici;, bölümünde, 70-75 C sıcaklıktaki asit ve baza dayanıklı katyer. değiştirici membran yapımı ve iyon geçirgenliğinin incelemesi gerçekleştirilmiştir. Bu membranın Türkiye'de bol miktarda bulunan boraks bileşiğinden, bir dış satım ürünü olan borik asit ile yurt gereksiniminin yarısı dış alım yolu ile karşılandı sodyum hidroksitin beraberce üretildiği membranlı elektroliz prosesinde kullanılabilmesi amaçlanmış tır. Yurt dışında, klor-alkali prosesinde kullanılmak üzere üretilen teflon esaslı xatyon değiştirici membranların fiyatları pahalıdır ve çok korrozif ortamlara dayanmak üzere yapıl mıştır. Boraks elektrolizi prosesinde klor gazı çıkmadığından ortam daha az korroziftir, bu nedenle teflon esaslı olmayan katyon değiştirici membranların da kullanılabilme olasılığı vardır. Çalışmada, önce polikondensasyonla katyon değiştirici membranlar hazırlanmış,, bunlardan anisolsülfonik asit-formaldehit esaslı meabranın proses koşullarına dayanıklı olduğu, ancak elektroliz perf ormi:V.s:.n:.?. 3'jşÜk olduğu saptanmıştır. Daha sonra yapılan sülfolanmış polistiren-polistiren-divinilbenzeninterpolimer katyon değiştirici membranların uygun divinilbenzen oranı için gerek proses koşullarına dayanıklılık, gerekse membranlı elektroliz performansı açısından başarılı olduğu görülmüştür. Bu interpolimer membranların, karşılaştırma için aynı proseste denen teflon esaslı (Nafion 324) ve polistiren- divinilbenzen esaslı ? methacryloxy gro.ps present. The analy< ical examination of the reaction products showed that the substitution reaction was a stepwise process. ( At the begining, the mono subs t itu ted siloxane molecules for- i med in the reaction mixture and after the completion of the monosubs t itut ion, disubs titu'ted siloxane molecules began to form in the expense of mono subs t itut ed molecules. The process repeated for further substitution, e.g. tr isubst i tuted mole cules increased, in the expense of disubstituted molecules. Some organic compounds such as ethyl. cellosolve and n-butanol having less steric hinderance produced tr isubst i :utedviii I siloxanes during trans es ter if icat ion reactions, however some others such as iso-butanol,. sec-butanol having brancned groups produced only mono and disubs t itutcd siloxanes. These new polymer izable silt xane monomers having long and branched pendant groups were copolymer ized with the esters of methacrylic acid to prepare mem>ranes having large free vo-lumes and high oxygen permeabilit i *s suitable to be used in biomedical applications. The siloxane monomers, esters of methacrylic 'acid (met hyl methacrylate or 2-hydroxyethyl meihacrylate), cross-linking agents (ethylene glycol dimethacrylat? or divinylbenzene) and trie initiator (pi, a' Azo^-iso-butyrilor.itr ile) were mixed for the desired composition in a flask. Tlıea, N` gas was allowed to pass for 5 minutes to remove the oxygen present in the co - monomer solution. The moulds were prepared by using glass plates, melinex sheets, polyethylene gaskets and metal clips. The co-monomer solution was injected with a syringe and a needle inside the glass plate mould. Then the mould was left in an oven for two days at 60 C ani for one day at 95 C. The thicknesses of the membranes were between 0,01-0,03, cm. The oxygen permeabilities of these membranes were mea sured with the polarographic electrode cell system, the wetta bilities of~the membrane surfaces were determined by measuring the water and methylene iodide.droplet contact angles using a special low power microscope, the critical surface tensions were cnlculnti'd from Fox and 7.ismnnn plot and the protein ab sorption properties were determined by microscopic examination of the pre-impr egna t ed membrane sanples in protein solutions. It was found that, there was an increase in oxygen per meabilities of the methyl methacry'le te copolymers formed with the use of high amounts of unsubst i tuted siloxane ( y -raethacy- loxypropyl trimethoxysilane), however the decrease of the wetta bility also acicompanied due to the hydrophobic nature of the siloxanes. When the cross-linking agent (ethylene glycol di- methacrylate) was used in high molar ratio, it was possible to introduce the siloxane monomers in high molar ratio, however excessive cross-linking decreased the oxygen permeability.IX The substitution of phenol, phenoxyacids and O-hydrox- yacids to siloxane compound produced jrigid and less oxygen per meable copolymers having hydrophobic surfaces. This was due to the lack of the free volume inside the copolymers because of the close packing of aromatic pendant groups and the effect of the intramolecular forces between polar groups. When the compounds having more (C-0) bonds in the mole cule substituted to the siloxane monomer, the high oxygen per meability was expected from the copolymers due to the flexibi lity of the (C-0) bond. However this assumption was not true, the longer the pendant group having (C-0) bonds gave less oxygen p_ermeable copolymers. The methacryloxy group containing siloxanes, after being substituted with ethylene glycol or diethylene glycol were found to copolymerize with hydrophilic monomers such as 2-hydroxyethyl methacrylate to give novel hydrogel copolymers having low water content. The copolymers, produced from the n-butanol substituted siloxane monomers with methyl methacrylate and ethylene glycol dimethacryla te had high oxygen permeabilities, whereas the copolymers produced from iso-butanol, sec-butanol substituted siloxane monomers had low oxygen permeabilities due to their low subs t itution` ratios. However, the assumption of obtaining high oxygen permeable copolymers by the substitution of branc hed alcohols was also valid as seen from the high oxygen per meable copolymers produced by the siloxane monomers having low substitution ratio of branched alcohols. It was required to examine other transesterif icat ion catalysts to obtain high substitution ratios for the reactions of branched alcohols with Y -methacryloxy propyl trimethoxy silane. The polarographic technique which was used in the measu rement of the `dissolved oxygen permeability coefficient` (Pd) of biomedical membranes gave frequently erroneous results, due to the stagnant boundary film formation at the polymer-liquid interface in the unstirred small cell and due to the electrode polarization, electrochemical side reactions during measure ment. A novel colorimetric technique that can overcome theseproblems and capable of measuring (?d) in a short time was de veloped within the scope of this work. The technique was de pended on the colorimetric determir ation of the dissolved oxy gen in the reduced indigo-carmine solution at 700 nm wavelength, The indigo-carmine solution, after being reduced by sodiüm dit- hionite was found very sensitive to oxygen oxidation and the color of the solution turned from transparent to deep blue within a short period of time. A plexiglass cell was constructed, seperating the air oxygen from the reduced indigo car sine ' solut ion by â polymer membrane whose permeability coefficient would be measured; in which the indigo carmine solution was stirred with a propeller to prevent the formation of boundary layers. An a asymptotic curve was obtained by the increase of the optical density with time, having the following relation: X-(X`-X0> d - e`at)+X0 where, X = optical density of the reduced indigo-carmine solution at time = t X = optical density of oxygen saturated indigo-carmine solution at time = 00 ' X = optical density of reduced indigo-carmine solution at time = p a = constant which depends on the oxygen permeability of the poiymeric membrane After the experimental determination of (X») an for the nearest approximation, max Since, the amount of maximum dissolved oxygen in water for a given temperature under atmospheric. conditions could be found from the published data, the `dissolved oxygen permeabi lity coefficient` (Pd) was calculated from the oxygen flux by Fick Law : Ap ApA t where, F = Flux of oxygen Ap = oxygen pressure difference across the membrane L = thickness of the membrane Q = volume of transported `xygen A = effective cross-sect ioaal area of the membrane sample The `dissolved oxygen permeability coefficients` of the polymers such as low density polyethylene, poly-4-methyl pent-1-ene, polystyrene, ethylene vir. acetate copolymer, siloxane-acrylate. copolymer were measured and were found in good agreement with the polarograph^c method result s. The co- lorimetric technique resulted in higher (P.) values for less permeable polymers than the poLarograpnic method due to the absence of the boundary layer formation by stirring the solu tion in the cell. There was better agreement for hi,ghly oxygen permeable polymers indicating the decrease of the effect of the' boundary layer formation for this type of polymers. In the second part of this work, the synthesis and the examination of the effect of the chemical and the macromolecu- lar structure of the cation exchange membranes on their per formances in the electrolysis of borax solution to produce boric acid and sodium hydroxide simultaneously was attempted. The borax solution was obtained by simple dissolution and filtration of tincal ore which was found in great reserves in Turkey. The membrane electrolysis cf borax solution should be carried out at 70-80°C for high production rates and thecation-exchange membranes should be resistant to acid and al kali at these temperatures.' The teflon based imported cation-exchang^ membranes which were used in chlor-alkali industry, were too expensive 2. (500-700 $/m ) and specially manufactured to resist the corro sive effect of chlorine gas produced. However as no chlorine gas was produced in the membrane electrolysis of borax, it was- possible to use a cheap and less resistant cation exchange membrane for this process. At the begining, the cation exchange membranes were synthesized by polycondensation reactions with functional group containing monomers and the membranes based oh anisole-. sulphonic acid, formaldehyde were round to be resistant to the process conditions, however they s lowed low performance during membrane electrolysis of borax solution due to their high water contents. The ion-exchange capacities of the polycon'densat ion mem branes increased with the increased amount of' sulphonation and with the decreased amount of formaldehyde molar ratio in the polycondensation composition. Similarly, the water contents of the membranes increased with the increased amount of sulp honation and the decreased amount of formaldehyde molar ratio. The attempts to prepare a cat ion-< xchange membrane having low water content and high ion-exohan:je capacity was unsuccesful because of this contradictory reason. Later, sulphonated polyethylene-polystyrene- diviniyl- benzene interpolymer membranes we 119

In this review, the purpose and the main role of ore sorting in mineral processing were outlined. General principles of operation were presented and the effect of development in electronics on the efficiency and flexibility of sorters was emphasised. Separation of valuable rocks from the waste using different properties such as reflectivity, emmission of gamma ray, fluorescense or infra red emmission under x-rays or UV light and conductivity was discussed. Applications of different sorters on various ores and especially on uranium ores were outlined together with the illustrations of specific separators. Finally, the future roles of radiometric ore sorters in uranium' processing were emphasised., Bu derlemede, otomatik tavuklayıcılar, kullanım amaçları ve cevher hazırlamadaki rolleri belirtilmektedir. Genel çalışma ilkeleri sunulurken elektronikteki hızlı gelişmenin tavuklayıcıların verimi ve uygulama esnekliği üzerindeki etkisi vurgulanmaktadır. Değerli minerallerin paşadan ayrılmasında kullanılan yansıma, gama ışınlarının yayılması, x - ışınları ya da mor ötesi ışınlar altında floresans veya kırmızı ötesi ışın yayma ve iletkenlik gibi özellikler tartışılmaktadır. Çeşitli tavuklayıcıların değişik cevherlere, özellikle uranyum cevherine uygulanmasına şekillerle değinilmektedir. Sonuç olarak radyometrik tavuklayıcıların gelecekte uranyum üretimindeki rolleri vurgulanmaktadır.

Bu çalışmada, alfa bozunumu hakkında bilgi verildi ve alfa parçacıkları için geçme katsayısını elde etmek için yeni bir yöntem uygulandı. Radyoaktif çekirdeklerin yarı ömürleri bu katsayı ile hesaplandı. Birinci, ikinci ve üçüncü bölümde alfa bozunumu incelendi ve alfa bozunum teorisi deneysel sonuçlarla tartışıldı. Daha sonra alfa bozunum teorisi için açısal momentum ve paritenin önemi ele alındı. Dördüncü bölümde, küresel simetrik potansiyeller için radyal S.D. nin yeni yöntemle çözümü anlatıldı. Yeni yöntemle elde edilen dalga fonksiyonları çizelge halinde verildi. Son bölümde ise, alfa bozunumu için geçme katsayısı hiçbir yaklaşım yapılmadan hesaplandı. Radyoaktif çekirdeklerin yeni yöntemle hesaplanan yarı ömürleri deneysel sonuçlarla karşılaştırıldı ve bu değerler çizelge halinde verildi.

V ÖZET DEFORME ÇEKİRDEKLERİN ENERJİ SEVİYELERİNİN NİLSSON POTANSİYELİ KULLANARAK YENİ YÖNTEMLE İNCELENMESİ KUNDURACI, Tank Yüksek Lisans Tezi, Fizik bölümü Tez Yöneticisi: Prof Dr. H. Hüseyin ERBİL 22 Ağustos 2003, 67 sayfa Yapılan çalışmada, deforme çekirdeklerin enerji değerlerinin deformasyon parametresine bağlı olarak nasıl değiştiği incelenmiştir. Elde edilen değerler, Nilsson'un yaptığı çalışma ile karşılaştırılmış, kullanılan yeni metodun daha küçük enerji değerleri ortaya koyduğu görülmüştür. İlk bölümde deformasyon parametresinin Kollektif Model vasıtasıyla elde edilişi anlatılmaktadır. İkinci bölümde ise Nilsson potansiyelinin ortaya konuşu ve deformasyon parametresinin potansiyel üzerindeki etkisi tartışılmaktadır. Ayrıca, literatürde sıkça karşılaşılan deformasyon parametrelerinin birbirleri cinsinden ifadeleri de kısaca anlatılmıştır. Son olarak, Nilsson'un yapmış olduğu çalışmalarda elde ettiği sonuçlar tablo halinde verilmiştir. Üçüncü bölümde, yeni yöntemle Schrödinger Denkteminin Radyal kısmının verilen bir potansiyel için çözülmesine, taban ve uyartılmış durumların enerji değerlerinin ve dalga fonksiyonunun nasıl belirleneceğine sırasıyla değinilmiştir. Son bölümde ise, ilk olarak çekirdek hamiltoniyeninin nasıl küreselleştirildiği detaylı bir şekilde açıklanmıştır. Daha sonra üstte bahsedilen yönteme başvurarak deforme çekirdekler için seviyelerin enerji değerleri hesaplanmış, Nilsson'un elde ettiği değerler ile karşılaştırmak amacıyla tablolar aracılığıyla verilmiştir. Anahtar sözcükler : Schrödinger Denklemi, Nilsson Yöntemi,Deforme Çekirdekler vn ABSTRACT AN INVESTIGATION OF THE ENERGY VALUES WITH THE NILSSON POTENTIAL IN THE DEFORMED NUCLEI BY APPLYING A NEW METHOD KUNDURACI, Tank MSc in Physic Dept. Supervisor: Prof. Dr. H. Hüseyin ERBİL 22 August 2003, 67 pages In this study, the change of the energy values has been analytically examined as a function of the deformation parameter in the deformed nuclei. The results have been compared with the results found by Nilsson and then, at the end of this comparison, it has been observed that the energy values found by the new method are smaller than the values found by Nilsson. In the first section, a commonly used method of the deformation parameter by using the Collective Model has been discussed. The way of establishing the Nilsson Potential and also the effect of the deformation parameter on this potential have been shown in the second section. Additionally, the relations between the other deformation parameters, which frequently occur in literature, have been shortly explained. Consequently, the results found by Nilsson have been given on a table at the end of this section. In the third section, for a given potential, an elaborate explanation about obtaining the ground state, exited state energies and the wave functions have been discussed. It has been also shown that how to determine the ground state and excited states energies and also the wave functions analytically. In the last section, the Ilamiltonian of a deformed nucleus has been converted into spherical form. Then, by applying the method mentioned above to the spherical potential, the required results of the energy values have been obtained. Finally, for making a good comparison, these energy values with the Nilsson's values have been given on the tables. Keywords:The Schrödinger Eq., The Nilsson method, Deformed Nuclei 67