Hüseyin Ata Karavana

An in vitro investigation for vaginal bioadhesive formulations: bioadhesive properties and swelling states of polymer mixtures.

Bioadhesive tablet formulations have been developed for mucosal application. Sixteen different bioadhesive tablet formulations were prepared and evaluated. Their bioadhesion to vaginal mucosa were studied by tensile testing method. The swelling behaviour of the tablets in three different solutions was also investigated. In addition, the effect of the formulations on pH of the medium was followed. The most favorable formulation resulted a mixture of Carbopol 934 and Pectin (2:1). The highest bioadhesive strength, the highest swelling volume and the lowest pH reduction were obtained with this formulation.

Comparison of different tanning agents on the stabilization of collagen via differential scanning calorimetry

Leather is composed of a three-dimensional weave of collagen fiber bundles. Collagen is a fibrous protein well organized in the formation of skin as building blocks. Leather production involves serial operations where the tanning plays the major role in improving the durability of leather products by stabilizing the triple helical structure of collagen matrix. In the leather-making industry, different tanning agents are used to produce different kind of leather goods. These tanning agents have varied efficiency on the stabilization of collagen. In this study, thermal stability of the leathers tanned with most commonly used tanning agents was evaluated by conventional shrinking test (CST) and differential scanning calorimetry (DSC) methods. The results showed that the thermal stability of leathers varied by the type of tanning agent which were in accordance with theoretical approaches. A distinct correlation was also observed between CST and DSC results of the tanned leathers.

An Alternative Evaluation Method for Swelling Studies of Bioadhesive Tablet Formulations

A new and alternative evaluation method is preferred for swelling studies of bioadhesive tablet formulations. CIELAB color coordinates, related to visual color response, are used for the first time to follow the swelling state and to calculate the swelling volume. The results are evaluated statistically. A simple equation is given to explain the relation between the swelling volume change % and color difference for three different bioadhesive formulations. It was found that the estimated equation is in good agreement with observed swelling volume results.

Farklı Proses Aşamasındaki Derilerin Diferansiyel Taramalı Kalorimetre ile Termal Davranışlarının Belirlenmesi ve Analiz Koşullarının Değerlendirilmesi

Calismada farkli proses asamasindaki derilerin termal davranislari cesitli kosullar altinda diferansiyel taramali kalorimetre (DSC) ile incelenmis ve derilerin hidrotermal stabilitesinin DSC ile tespit edilebilirligi arastirilmistir. Bu amacla oncelikle ham deri, pikle, tabaklanmis ve mamul haldeki derilerin hidrotermal stabilitesi, buzulme sicakligi standart testi ile analiz edilerek belirlenmistir. Ardindan ayni deri ornekleri farkli kosullandirma parametreleri kullanilarak kuru ve yas formda DSC metodu ile analiz edilmistir. Elde edilen veriler; 24 saat kosullandirilmis ve basinca dayanikli kaplar icerisinde, sulu ortamda, 25-150 oC araliginda analiz edilen deri orneklerinin en iyi sonuclari verdigini gostermistir. Ayni zamanda mevcut kosullardaki DSC termogramlarindan elde edilen verilerin, derilerin standart metot ile elde edilen buzulme sicakligi (Ts) degerleri ile paralellik gosterdigi tespit edilmistir.

Synthesis and characterization of functional acrylic copolymers via RAFT mini-emulsion polymerization

Copolymers bearing reactive functional groups with controlled molecular weights are of importance since they can be used in many fields such as composites, coatings, membranes, catalysis, biology, optoelectronics, pharmaceuticals, etc. In the present study low molecular weight copolymers based on butyl acrylate (BA) and methyl methacrylate (MMA) in combination with reactive functional monomers of vinyl trietoxysilane (VTES), 3-trimetoxysilylpropyl methacrylate (TMSPMA) and glycidyl methacrylate (GMA) were synthesized via RAFT mini-emulsion technique using 2-cyano 2-propyldodecyldithiocarbonate as CTA agent. The results showed that the average molecular weights of copolymers were close to the theoretical values. On the other hand, PDI values were found to be higher than conventional RAFT polymers. The particle sizes of the latexes were small with very homogenous distributions and good stability. FTIR, H-NMR and TGA results verified the success of copolymer syntheses.

The influence of the rocker sole profile's orientation on the sagittal plane ankle range of motion

Rocker shoes are prescribed in any pathomechanical condition where the normal motions of the foots joints are limited, as it is the case with hallux limitus/rigidus or ankle immobilisation. Walking is achieved through facilitating the movement around the three pivoting centres: heel, ankle and metatarsophalangeal joints. One important technical parameter of the rocker sole profiles is represented by the position of the distal and proximal borders of the contact area between sole and supporting surface. The design of rocker soles profiles based on the concept of invariability of the roll-over shape of the ankle-foot system during walking implies that the soles sagittal plane profile will have a circular shape, with identical distal and proximal borders. The aim of this study was to evaluate the influence of the orientation of rocker sole profile on the ankles sagittal plane range of motion.

Sturgeon Skins A Valuable Resource for Luxury Leather Industry

STURGEON SKINS – A VALUABLE RESOURCE FOR LUXURY LEATHER INDUSTRY ABSTRACT. This research paper presents sturgeon skins as a valuable resource for the luxury leather industry. Although less known for their use in the field of leather garments, sturgeon skins show a distinct alternation between skin and bony shields that suggests the possibility of manufacturing fashion accessories in the current fashion trends. The difficulty of processing technologies results from the peculiar structure of the skin without scales, but rich in bony protrusions. The paper presents the main characteristics of sturgeon skin processing, physical-mechanical and chemical properties, as well as the possibility of manufacturing luxury accessories. Research suggests a superior utilization of a byproduct of the fish processing industry and brings original contributions to knowledge regarding the properties of sturgeon skins.