Yazar "Aslan, A." seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe THE CHARACTERISTICS AND EATING HABITS OF 2 TO 6-YEAR-OLD CHILDREN WITH FOOD REFUSAL(Lippincott Williams & Wilkins, 2010) Akman, S. A.; Halicioglu, O.; Koturoglu, G.; Koc, F.; Aslan, A.; Sutcuoglu, S.; Arikan, C.; Kurugol, Z.Öğe Dye Incorporated Nanopolymers and their Application to Leather Wastewater: A Study of Removal of Cr(III) Ions(Soc Leather Technol Chemists, 2016) Acikel, S. M.; Feyzioglu, E.; Kuru, C. I.; Turker, E.; Aslan, A.; Uygun, D. Aktas; Akgol, S.In this presented work, Alkali Blue 6B-attached poly(2-hydroxyethyl methacrylate) nanopolymers (nano-PHEMA-AB) were synthesized as an adsorbent for the removal of the heavy metal Cr(III) from leather wastewater. For this purpose, first PHEMA nanopolymers were prepared by surfactant free emulsion polymerization. Alkali Blue 6B was then covalently attached to the PHEMA nanopolymers. Characterization of the nano-PHEMA-ABs was carried out by elemental analysis, SEM, FT-IR and Zeta Size analysis. The specific surface area of nano-PHEMA-AB was calculated to be 1131.2m(2)/g. The optimum adsorption conditions (Le. adsorption capacity, medium pH, adsorption rate) were studied and reusability of nano-PHEMA-AB was also determined. The maximum Cr(III) adsorption capacity of nano-PHEMA-AB was found to be 4755.9mg/g at pH3.8. Additionally synthesized nano-PHEMA-AB were used for the removal of Cr(III) ions from chrome tanning wastewater and Cr(III) removal capacity of the nanopolymer was found to be 2724.2mg/g at pH3.9. According to the results, dye incorporated PHEMA nanopolymers can be used as an effective, re-usable remover of Cr(III) from leather wastewater due to their large surface area and high adsorption capacity.Öğe Heavy metal contents of various finished leathers(Soc Leather Technol Chemists, 2006) Basaran, B.; Iscan, M.; Bitlisli, B. O.; Aslan, A.In this study, an investigation was made into the heavy metal content of leather articles. The metals concerned were cobalt, chromium, copper, zinc, lead and nickel as these metals may be subject to restrictions in some products because of their toxic characteristics. Insole leathers, upper leathers and garment leathers were studied as likely contaminating sources because of their extensive contact with the human body. Total amounts of heavy metals were initially measured by digestion. In addition, the possible amounts of heavy metals which would easily be extracted in use were extracted in aqueous and artificial perspiration solutions and analyzed using ICP-AES. It was concluded that the heavy metal content of finished leathers depended mainly on the chemicals used in production, and in particular high chromium contents in leather goods were determined. Also, small amounts of cadmium, zinc, lead, cobalt and copper were detected due to chemical and physical reactions during dyeing and finishing processes. The results of heavy metal contents were compared with limit values for leather and textile articles.Öğe Increased chromium tanning efficiency with collagen hydrolysates(Soc Leather Technol Chemists, 2006) Aslan, A.; Gueluemser, G.; Ocak, B.Collagen hydrolysates obtained from shavings of chrome tanned sheep skins were used in a pretanning process for sheepskins and the effect on the efficiency of chrome tanning was observed. Various physical tests and chemical analyses were applied to tanned sheepskins and the results were evaluated statistically. Wet-blue leathers pretanned with 5% protein by-product (collagen hydrolysates) showed increased chromium take-up and had better physical characteristics.Öğe Reduction of Yellowing Effect on Leathers with UV Absorber Benzophenone-4(Soc Leather Technol Chemists, 2016) Acikel, S. M.; Aslan, A.Besides quality in leather manufacture, another important factor is that the customer should use the product in the long term without any problem. However, a leather product, being a natural structure, can age because of environmental conditions such as UV, temperature, and humidity, and its chemical and physical structure can change with time. Some leather products in particular such as upholstery leathers which are exposed to sunlight can be aged and yellowed by the effects of UV light and temperature. Therefore, there is a need to prevent ageing and yellowing. UV absorbers are often used in various products such as cosmetics and polymeric materials to prevent the destructive effects of ultraviolet radiation. The aim of this work was to study use of the UV absorber benzophenone-4 in reducing yellowing. Chrome-tanned and vegetable-tanned crust leathers were given a coating of hydro lacquer [lacquer emulsion] including the UV absorber benzophenone-4 as a finishing process. After exposure to monochromatic UV light at a wavelength of 340nm for 24, 48, 72, 96, 120, 144 or 168 hours at approximately 80 degrees C. The results were investigated by CIE Lab Colour measurement and by FTIR-ATR spectrophotometer.Öğe Removal of Acid Black 210 Dye from Leather Dyeing Effluent using Spherical Particles of P(HEMA-GMA)IDA-Cr(III) Hydrogel Membrane(Soc Leather Technol Chemists, 2017) Acikel, S. M.; Senay, R. H.; Akgol, S.; Aslan, A.Hydrogel membranes can swell by a high proportion of their weight and have a large surface area, and are nowadays preferred in adsorption studies. In this work, p(HEMA-GMA) poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) spherical particulated hydrogel membrane (SPM) was produced by UV photopolymerization and the synthesized membrane was coupled with iminodiacetic acid (IDA) in order to bond the Cr(III) ions in the chrome tanning process effluent. Then p(HEMA-GMA)-IDA-Cr(III) SPM was used to remove Acid Black 210 dye from the dyeing process effluent. The membrane's chrome and dye adsorption capacities were determined using a UV/Vis Spectrophotometer at wavelengths of 601nm and 435nm respectively. After the membranes were used, the discharged tanning and dye process wastewaters were examined in order to see the differences in the wastewater in terms of COD, BOD5, conductivity, pH, salinity, total dissolved solids, total suspended solids, potassium, total nitrogen and chromium content. The results showed that the metal-chelated p(HEMA-GMA)-IDA SPMs chelated chrome ions between 398.47 and 619.10mg/g, and the adsorbed Acid Black 210 dye molecules were between 0.76 and 1.87mg/g. In conclusion, p(HEMA-GMA)-IDA SPM is an effective sorbent system for removing Cr(III) ions and acid dye molecules from leather discharge waters.Öğe Use of Silk Hydrolysate in Chrome Tanning(Soc Leather Technol Chemists, 2014) Aslan, G. Itirli; Gulumser, G.; Ocak, B.; Aslan, A.This study examined the characteristics and environmental load of sheep skins that had been treated with silk hydrolysate by two different methods: prior to tannage and after tannage. Silk hydrolysate was applied to the leathers before and after tanning in four different proportions. The chrome oxide content and shrinkage temperature, tensile strength and tear load of the leathers increased as the proportion of silk hydrolysate increased, and the highest levels of chrome exhaustion in the tanning effluents were obtained at an application level of 5% on the basis of leather weight. In addition, silk hydrolysate was found to improve wastewater parameters such as chemical oxygen demand, total suspended solids, total dissolved solids, salinity and electrical conductivity.Öğe Utilization of collagen hydrolysate in keratinase production from Bacillus subtilis ATCC 6633(Amer Leather Chemists Assn, 2007) Aslan, A.; Karavana, H. A.; Gulumser, G.; Yasa, I.; Cadirci, B. H.In this study, chrome shavings from the tanning industry were hydrolyzed with a commercial protease in alkali medium. Some chemical analyses were made and amino acid composition of collagen hydrolysate obtained from chrome shavings determinations. This collagen hydrolysate was used for the production of keratinase from Bacillus subtilis ATCC 6633 as a carbon and nitrogen source. The culture grew in fermentation medium containing various proportion of collagen hydrolysate (1-5% w/v) at pH 7.0 and pH 10.0 with agitation rate of 200 rpm. The best keratinase production was obtained from the medium containing 1% hydrolysate (w/v) at pH 7.0 for 36 hours and with 3% hydrolysate (w/v) at pH 10.0 for 24 hours.
