Browsing by Author "Özkan O."

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Characteristics of a protective layer on oil heat-treated scots pine and fir wood
(2017-05-01) Kesik H.; Özkan O.; Öncel M.
Effects of natural weathering were studied relative to the adhesion strength, surface hardness, and color change of coated heat-treated and untreated Turkish fir and Scots pine wood. For this study, water-based coatings (varnish and paint) were applied on heat-treated samples. The coated heat-treated, and untreated samples were naturally weathered for one year. The difference between several properties such as adhesion strength, hardness, and color were measured before and after weathering. The test results showed that varnished heat-treated samples had good performance as compared to those of the untreated samples.
Chemical composition and antimicrobial activity in cold press oil of fennel, anise, white and black mustard seeds
(2017-07-01) Olgun Ç.; Özkan O.; Güney B.; Pattabanoglu E.; Güney K.; Gür M.
In this study, the cold press oil components and antimicrobial activities of fennel (Foeniculum vulgare) and anise (Pimpinella anisum) and white mustard (Sinapis alba) and black mustard (Brassica nigra) species seeds, which are widely used by the people for alternative medicine, were determined. F. vulgare, P. anisum, S. alba and B. nigra species seeds were obtained from cultivated areas in central Anatolia in Turkey. The oil was extracted by using a screw press (MP-001 Cold Press, Turkey), and the volatile oil components and fatty acid components in these oils were analysed by GCMS and total phenolic content, total flavonoid content and antioxidant activities by DPPH and FRAP (%) method were determined. Antimicrobial activities of obtained oils were investigated by using minimum inhibitory concentration (MIC) test by against 18 different species microorganisms. In the GCMS results, F. vulgare and P. anisum oils were found to be the most abundant components which were anethole (89.74%, 88.95%, respectively). According to these results, the plants oils didn’t show any antimicrobial activities against tested microorganisms. However especially white and black mustard oils showed strong antioxidant activity when compared with artificial antioxidants.
Determination of antimicrobial activity and chemical composition of pimento & ginger essential oil
(2017-07-01) Şener N.; Özkinali S.; Gür M.; Güney K.; Özkan O.; Khalifa M.
The essential oil was obtained from pimento (Pimenta racemosa Mill.) and ginger (Zingiber officinale Rosc.) through hydrodistillation method. The chemical composition of pimento and ginger essential oils were analyzed by GC-MS. It was found that the most abundant components were methyleugenol (52.33%) and zingiberene (16.32%) in essential oils of pimento and ginger, respectively. The antimicrobial activities of essential oils were investigated against 18 microorganisms with minimum inhibitory concentration (MIC) method. While pimento essential oil behaved strong antimicrobial against all bacteria apart from S. epidermidis, ginger essential oil exhibited poor activity against all bacteria. As a result of this study; it can be suggested that pimento essential oil is a preservative in the medicinal application and food industry.
Effect Of dill (Anethum graveolens) and garden cress (Lepidium sativum) dietary supplementation on growth performance, digestive enzyme activities and immune responses of juvenile common carp (Cyprinus carpio)
(2018-10-01) Bilen S.; Özkan O.; Alagöz K.; Özdemir K.
In this study, Bilen et all, studied that the effect of dietary supplementation of dill (Anethum graveolens) and garden cress (Lepidium sativum) on the growth performance, digestive enzyme activities and immune responses of juvenile common carp (Cyprinus carpio) in addition to their disease resistance to Aeromonas hydrophila and Edwardsiella tarda. Common carp were fed for 45 days with two different doses of extracts of plant (1 and 2 g kg−1) in four treatment groups: dill 1 g kg−1 (D1) and 2 g kg−1 (D2) and garden cress 1 g kg−1 (G1) and 2 g kg−1 (G2). At the end of the study, the fish were challenged with A. hydrophila and E. tarda. Results showed that the final fish weight and specific growth rates were higher in the G2 group than in the control group (C) and other experimental groups (D1, D2 and G1) (P < 0.05). Compared with the control group, there were no differences in the feed conversion ratio (FCR) in the experimental groups, except the D1 group, (P > 0.05). In the D1 group, FCR was significantly increased. Trypsin activity was significantly decreased in the G2 group. Compared with the control group, amylase activity was the highest in the D2 group (P < 0.05). There were no differences in lipase activities among the groups. Lysozyme activity was significantly increased on the 15th day of the study in D1 and G2 groups compared with that in the control group (P < 0.05). On the 30th day, lysozyme activity was increased in the D2 group compared with that in the control group (P < 0.05). No differences were observed in lysozyme activity among the groups on the 45th day. Myeloperoxidase (MPO) activity was elevated in the G2 group on the 15th day (P < 0.05). The highest MPO activity was observed in the D1 group (P < 0.05) on the 30th day of the study. On the 45th day, the MPO activity in all experimental group's (P < 0.05) was higher than that in the control group. At any sampling time of the study, superoxide anion production was elevated in all experimental groups compared with that in the control group. Moreover, when challenged with A. hydrophila, survival rates of common carp in G1, G2 and D1 groups were significantly increased, and when challenged with E. tarda, those of common carp in G2 and D1 groups were also elevated. The results of the study showed that cress had immunostimulatory effects in common carp and increased the fishes’ growth rate.
Essential oil of oregano and savory; chemical composition and antimicrobial activity
(2017-07-01) Özkan O.; Güney K.; Gür M.; Pattabanoğlu E.; Babat E.; Khalifa M.
The essential oils of oregano (Origanum vulgare ssp. hirtum) and savory (Satureja thymbra) plants were obtained through steam distillation method. The chemical compositions of their essential oils were analyzed via GC-MS technique. Furthermore, their antimicrobial activities were studied by using minimum inhibitory concentration (MIC) method. Their chemical composition was found as carvacrol (63.97%), p-cymene (12.63%) and linalool (3.67%) in oregano essential oil as major compounds and also, as carvacrol (42.7%), o-cymene (17.98%), linalool (9.65%), caryophyllene oxide (5.25%) and γ-terpinene (4.22%) in savory essential oil as major compounds. As a result, it can be said that that oregano and savory essential oil may be useful in the medicinal application and food industry as a preservative against harmful microorganisms.
The tensile shear strength of outdoor type plywood produced from fir, alnus, pine and poplar wood
(2019-01-01) Öncel M.; Vurdu H.; Aydoğan H.; Özkan O.; Kaymakci A.
In this study, it is aimed to determine both the tensile-shear strengths of plywood that produced by using phenol formaldehyde resin from Uludağ fir (Abies nordmanniana subsp. bornmülleriana Mattf.), alder (Alnus glutinosa L.), scots pine (Pinus sylvestris L.) and Samsun poplar (77/51 Populus deltoides Bartr.) trees rotary cut veneers combinations of poplar-pine, poplar-fir, poplar-alder and poplar wood along with the effect of wood types on adhesion quality of glue. According to standards TS 3969 EN 314-1, and TS EN 314-2 adhesion class 3, the test specimens were prepared and tested for the adhesion quality. The obtained data were analyzed statistically by using SPSS 22 statistical program. As a result, the tensile-shear strength values of poplar, pine-poplar, fir- poplar and alder-poplar plywood types were found to be as averages 1.34 N.mm-2, 1.66 N.mm-2, 2.18 N.mm-2 and 2.46 N.mm-2 respectively. Also, it was found that there was no significant difference between the alder poplar and fir-poplar plywood types about tensile-shear strength. Since these all plywood combinations are satisfied the required 1 N.mm-2 strength value according to TS EN 314-2, all plywood types in this study are of suitable quality for outdoor uses.