Araştırma Makalesi
Yıl 2019,
Cilt: 20 Sayı: 4, 458 - 465, 27.12.2019
Öz
Bu çalışmada, biyobazlı tanen tutkalı üretimi yapılmıştır. Biyotutkal sentezinde kullanılan tanenler orman işletmelerinde kesim sonrası ortaya çıkan ladin (Picea orientalis) kabuğu ve ahşap levha endüstrisinde üretim sonrası ortaya çıkan atık meşe (Quercus spp.) kabuklarından elde edilmiştir. Ekstraksiyon sonrası elde edilen çözeltiler kullanılarak sprey kurutucuda toz tanen üretimi yapılmıştır. Üretilen ladin ve meşe tanenlerinin fenolik bileşimini ortaya koymak için tanen analizleri gerçekleştirilmiştir. Sonraki aşamada ladin ve meşe taneni kullanılarak biyotutkal sentez denemeleri yapılmıştır. Bu denemelerde sıcaklık, pH, formaldehit tanen molar oranı, viskozite, serbest formaldehit miktarı gibi parametreler optimize edilmiştir. Ardından üretilen tutkalın özellikleri ortaya konmuştur. Son olarak biyotutkalın yapışma performansı lap shear testi ile belirlenmiştir. Biyotutkal üretim denemeleri sonuçlarına göre, formaldehit tanen molar oranının tutkaldaki serbest formaldehit miktarı ve tutkalın raf ömrü üzerinde oldukça etkili olduğu anlaşılmıştır. Sentezlenen biyotutkal formülasyonlarında ladin için en yüksek raf ömrü 72 gün iken meşe için 38 gün olarak gerçekleşmiştir. pH’a bağlı jel zamanı değişimi de incelenmiş, ladin ve meşe sülfit tanenlerinin su taneninden %12 daha yüksek jel zamanına sahip olduğu ortaya konulmuştur. Lap shear testi sonuçlarına göre, ladin tanen tutkalı ticari fenol formaldehit tutkalına benzer yapışma performansına sahip olduğu görülmüştür.
Anahtar Kelimeler
Destekleyen Kurum
İstanbul Üniversitesi Bilimsel Araştırma Projeleri Birimi
Proje Numarası
T-22881
Teşekkür
Bu çalışma İstanbul Üniversitesi Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir (Proje no: T-22881).
Kaynakça
- Ayla, C., 1978. Tanen-formaldehit yapıştırıcıları, yurdumuz açısından önemi, Pinus brutia kabuk ekstraktı ile yapılan ön çalışmalar. İstanbul Üniversitesi Orman Fakültesi Dergisi, A Serisi, Cilt:28, Sayı:1.
- Ayla, C., Parameswaran, N., 1980. Macro- and microtechnological studies on beechwood panels bonded with Pinus brutia bark tannin. Holz als Roh- und Werkstoff, 38, 449-459.
- Bate-Smith, E.C., 1972. Detection and determination of ellagitannins. Phytochemistry, 11: 1153-1156.
- BSI 5350-B2, 1976. Methods of test for adhesives: Determination of solids content. British Standards Institute, London.
- Cadahia, E., Varea, S., Munoz, L., Simon, B.F., Vallejo, M.C.G., 2001. Evolution of ellagitannins in Spanish, French, and American oak woods during natural seasoning and toasting. Journal of Agricultural and Food Chemistry, 49: 3677-3684.
- Chupin, L., Motillon, C., Bouhtoury, C.E., Pizzi, A., Charrier, B., 2013. Characterization of maritime pine (Pinus pinaster) bark tannins extracted under different conditions by spectroscopic methods, FTIR and HPLC. Industrial Crops and Products, 49: 897– 903.
- Dönmez, İ.E., Dönmez, Ş., 2013. Ağaç kabuğunun yapısı ve yararlanma imkânları. Süleyman Demirel Üniversitesi, Orman Fakültesi Dergisi, 14: 156-162.
- Edelmann, A., Lendl, B., 2002. Toward the optical tongue: Flow-through sensing of tannin− protein interactions based on FTIR spectroscopy. Journal of the American Chemical Society, 124(49): 14741-14747.
- Fengel, D., Wegener, G., 1984. Wood Chemistry, Ultrastructure, Reactions. Walter de Gruyter, Berlin New York, 3-11-008481-3.
- Frihart, C., 2000. Biobased Adhesives and Non-Convential Bonding. Forest Products Laboratory, Madison, WI 53726, USA.
- Galvez, J.M.G., Riedl, B., Conner, A.H., 1997. Analytical studies on tara tannins. Holzforschung, 51: 235-243.
- Gordon-Gray, C.G., 1957. A comparison of the results of estimating black wattle tannin by the official hide powder method and a proposed ultraviolet spectrophotometric method. Journal of the Society of Leather Trades Chemists, 41: 269-275.
- Govindarajan, V.S., Mathew, A.G., 1965. Anthocyanidins from leucoanthocyanidins, Phytochemistry, 4: 985-988.
- Gönültaş, O., Balaban Uçar, M., 2012. Fıstıkçamı (Pinus pinea) kabuğunun tanen bileşimi. KSÜ Doğa Bilimleri Dergisi, Özel Sayı: 80-84.
- Gönültaş, O., 2013. Doğu ladini (Picea orientalis) ve meşe (Quercus spp.) kabukları taneninin biotutkal üretiminde kullanılması. Doktora tezi, İstanbul Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul.
- Gönültaş, O., Uçar, M.B. 2018. Doğu ladini ve meşe kabuklarından tanen ekstraksiyon aşamasının optimize edilmesi. Türkiye Ormancılık Dergisi, 19(3): 323-329.
- Giurginca, M., Badea, N., Miu, L., Meghea, A., 2007. Spectral technics for identifying tanning agents in the heritage leather Items. Revista De Chimie-Bucharest-Original Edition, 58(9): 923-928.
- Hoong, Y.B., Paridah, M.D.T., Luqman, C.A., Koh, M.P., Loh, Y.F., 2009. Fortification of sulfited tannin from the Bark of Acacia mangium with phenol-formaldehyde for use as plywood adhesive. Industrial Crops and Products, 30: 416-421.
- Hu, R., Lin, L., Liu, T., Ouyang, P., He, B., Liu, S., 2008. Reducing sugar content in hemicellolose hydrolysate by DNS method: A revisit. Journal of Biobased Materials and Bioenergy, 2: 156-161.
- Ignat, I, Volf, I., Popa, V.I., 2011. Characterization of extractives from some raw materials processed by biorefining. COST Meeting, 25-26 January, Paris.
- Inoue, K. H., Hagerman, A. E., 1988. Determination of gallotannin with rhodanine. Analytical biochemistry, 169(2): 363-369.
- Khanbabaee, K., Ree, T.V., 2001. Tannins: Classification and definition. Natural Product Reports, 18: 641–649.
- Kim, S., 2003. Adhesion properties and curing behaviors of pine and wattle tannin-based adhesives, Thesis for The Degree of Master of Science, Seoul National University, Department of Forest Product Graduate School, Seul, North Korea.
- Kim, S., Kim, H. J., 2003. Curing behavior and viscoelastic properties of pine and wattle tannin-based adhesives studied by dynamic mechanical thermal analysis and FT-IR-ATR spectroscopy. Journal of adhesion science and technology, 17(10): 1369-1383.
- Laghi, L., Parpinello, G.P., Rio, D.D., Calani, L., Mattioli, A.U., Versari, A., 2010. Fingerprint of enological tannins by multiple techniques approach. Food Chemistry, 121: 783–788.
- Lee, W.J., Lan, W.C., 2006. Properties of resorcinol-tannin-formaldehyde copolymer resins prepared from the bark Extracts of Taiwan acacia and China fir. Bioresource Technology, 97: 257-264.
- Leyser, E., 1990. The formulation and commercialization of glulam pine tannin adhesives in Chile. Holz als Roh- und Werkstoff, 48: 25-29.
- Liiri, O., Sairanen, H., Kilpelainen, H., Kivisto, A., 1982. Bark extractives from Spruce as constitutes of plywood bonding agents. Holz als Roh- und Werkstoff, 40: 51-60.
- Miller, G.L., 1959. Use of DNS reagent for determination of reducing sugars. Analytical Chemistry, 31: 426-438.
- Ooa, C.W., Kassima, M.J., Pizzi, A., 2009. Characterization and performance of Rhizophora apiculata mangrove polyflavonoid tannins in the adsorption of copper (II) and lead (II). Industrial Crops and Products, 30: 152–161.
- Özacar, M., Soykan, C., Sengil, İ.A., 2006. Studies on synthesis, characterization, and metal adsorption of mimosa and valonia tannin resins. Journal of Applied Polymer Science, 102: 786–797.
- Pena, C., Larranaga, M., Gabilondo, N., Tejado, A., Echeverria, M., Mondragon, I., 2006. Synthesis and characterization of phenolic novolacs modified by chesnut and mimosa tannin extracts. Journal of Applied Polymer Science, 100: 4412-4419.
- Ping, L., Pizzi, A., Guo, Z.D., Brosse, N., 2012. Condensed tannins from grape pomace: Characterization by FTIR and MALDI TOF and production of environment friendly wood adhesive. Industrial Crops and Products, 40: 13– 20.
- Pizzi, A., 1983. Wood Adhesives Chemistry and Technology. Marcel Dekker: New York, vol. 1, 0-8247-1579-9.
- Pizzi, A., Leyser, E.P., Valenzuela, J., Clark, J.G., 1993. The chemistry and development of pine tannin adhesives for exterior particleboard. Holzforschung, 47: 168-174.
- Pizzi, A., 1994. Advanced Wood Adhesives Technology. Marcel Dekker Inc., New York, 978-0824-7926-64.
- Pizzi, A., Stephanou, A., 1994. Fast vs. slow-reacting non-modified tannin extracts for exterior particleboard adhesives. Holz als Roh- und Werkstoff, 52: 218-222.
- Pizzi, A., Mittal, K.L., 2003. Handbook of Adhesive Technology. Second Edition, Revised and Expanded, Marcel Dekker, New York, 0-8247-0986-1.
- Puica, N.M., Pui, A., Florescu, M., 2006. FTIR spectroscopy for the analysis of vegetable tanned ancient leather. European Journal of Science and Theology, 2(4): 49-53.
- Roffael, E., Dix, B., Okum, J., 2000. Use of spruce tannin as a binder in particleboards and medium density fiberboards (MDF). Holz als Roh- und Werkstoff, 301-305.
- Roux, D.G., 1951. Photometric method of tannins analysis for black wattle tannins. Journal of the Society of Leather Trade Chemists, 35: 322.
- Scalbert, A., Haslam, E., 1987. Polyphenols and chemical defence of the leaves of Quercus robur. Phytochemistry, 26: 3191-3195.
- Singleton, V.L., Rossi, J.A., 1965. Colorimetry of total phenolics with phosphomolybdicphosphotungstic acid reagents. American Journal of Enology and Viticulture, 16: 144-158.
- Valenzula, J., Leyser, E.V., Pizzi, A., Westermeyer, C., Gorrini, B., 2012. Industrial Production of Pine Tannin-Bonded Particleboard and MDF. European Journal of Wood and Wood Products, 70: 735–740.
- Vazquez, G., Antorrena, G., Gonzalez, J., Alvarez, J.C., 1996. Tannin-based adhesives for bonding high-moisture Eucalyptus veneers: Influence of tannin extraction and press conditions. Holz als Roh- und Werkstoff, 54: 93-97.
- Vazquez, G., Alverez, J.G., Freire, S., Suevos, F.L., Antorrena, G., 2001. Characteristics of Pinus pinaster bark extracts obtained under various extraction conditions. Holz als Roh- und Werkstoff, 59: 451.
- Vazquez, G., Alvarez, J.G., Suevos, F.L., Antorrena, G., 2002. Rheology of tannin-added phenol formaldehyde adhesives for plywood. Holz als Roh- und Werkstoff, 60: 88-91.
- Vazquez, G., Alvarez, J.G., Santos, J., Freire, M.S., Antorrena, G., 2009. Evaluation of potential applications for chesnut (Castanea sativa) shell and eucalyptus (Eucalyptus globus) bark extracts. Industrial Crops and Products, 29, 364-370.
- Yazaki, Y., Hillis, W.E., 1977. Polyphenolic extractives of Pinus radiata bark. Holzforschung, 31(1): 20-25.
- Yazaki, Y., Collins, P.J., 1994. Wood adhesives from Pinus radiata bark. Holz als Roh- und Werkstoff, 52: 185-190.
- Yurtsever, M., Şengil, İ.A., 2012. Adsorption and desorption behavior of silver ions onto valonia tannin resin. Transactions Nonferrous Metals Society of China, 22: 2846-2854.
Yıl 2019,
Cilt: 20 Sayı: 4, 458 - 465, 27.12.2019
Öz
In this research, bio-based tannin adhesives were developed by using tannins from spruce (Picea orientalis) and oak (Quercus spp.). The barks were obtained from wood-based panel industry and forest residues. The tannin powders were produced with a spray dryer based on the observations during the extraction process. Chemical analyzes were performed to determine the phenolic content of the spruce and oak tannins. After that bioadhesive synthesis experimentals were carried out using the spruce and oak tannins. In the experimentals, the bioadhesive synthesis parameters such as pH, formaldehyde:tannin molar ratio, viscosity, and free formaldehyde content were optimized. Finally, the adhesion performances of the bioadhesives were determined with the lap shear test. The results obtained in this work clearly showed that the shelf life and free formaldehyde content values of the adhesives were affected by the formaldehyde:tannin molar ratios. As for the maximum shelf life values of the bioadhesives, the spruce tannin adhesive had 72 days shelf life, whereas the oak tannin adhesive had 38 days. The gelation time values related with pH were also examined. The findings demonstrated that the spruce and oak sulfited tannins had 12% higher gelation time values than those of the water tannins. According to the results of the lap shear test, the spruce tannin based bioadhesives had similar adhesion performance as compared with a commercial phenol formaldehyde adhesive.
Anahtar Kelimeler
Proje Numarası
T-22881
Kaynakça
- Ayla, C., 1978. Tanen-formaldehit yapıştırıcıları, yurdumuz açısından önemi, Pinus brutia kabuk ekstraktı ile yapılan ön çalışmalar. İstanbul Üniversitesi Orman Fakültesi Dergisi, A Serisi, Cilt:28, Sayı:1.
- Ayla, C., Parameswaran, N., 1980. Macro- and microtechnological studies on beechwood panels bonded with Pinus brutia bark tannin. Holz als Roh- und Werkstoff, 38, 449-459.
- Bate-Smith, E.C., 1972. Detection and determination of ellagitannins. Phytochemistry, 11: 1153-1156.
- BSI 5350-B2, 1976. Methods of test for adhesives: Determination of solids content. British Standards Institute, London.
- Cadahia, E., Varea, S., Munoz, L., Simon, B.F., Vallejo, M.C.G., 2001. Evolution of ellagitannins in Spanish, French, and American oak woods during natural seasoning and toasting. Journal of Agricultural and Food Chemistry, 49: 3677-3684.
- Chupin, L., Motillon, C., Bouhtoury, C.E., Pizzi, A., Charrier, B., 2013. Characterization of maritime pine (Pinus pinaster) bark tannins extracted under different conditions by spectroscopic methods, FTIR and HPLC. Industrial Crops and Products, 49: 897– 903.
- Dönmez, İ.E., Dönmez, Ş., 2013. Ağaç kabuğunun yapısı ve yararlanma imkânları. Süleyman Demirel Üniversitesi, Orman Fakültesi Dergisi, 14: 156-162.
- Edelmann, A., Lendl, B., 2002. Toward the optical tongue: Flow-through sensing of tannin− protein interactions based on FTIR spectroscopy. Journal of the American Chemical Society, 124(49): 14741-14747.
- Fengel, D., Wegener, G., 1984. Wood Chemistry, Ultrastructure, Reactions. Walter de Gruyter, Berlin New York, 3-11-008481-3.
- Frihart, C., 2000. Biobased Adhesives and Non-Convential Bonding. Forest Products Laboratory, Madison, WI 53726, USA.
- Galvez, J.M.G., Riedl, B., Conner, A.H., 1997. Analytical studies on tara tannins. Holzforschung, 51: 235-243.
- Gordon-Gray, C.G., 1957. A comparison of the results of estimating black wattle tannin by the official hide powder method and a proposed ultraviolet spectrophotometric method. Journal of the Society of Leather Trades Chemists, 41: 269-275.
- Govindarajan, V.S., Mathew, A.G., 1965. Anthocyanidins from leucoanthocyanidins, Phytochemistry, 4: 985-988.
- Gönültaş, O., Balaban Uçar, M., 2012. Fıstıkçamı (Pinus pinea) kabuğunun tanen bileşimi. KSÜ Doğa Bilimleri Dergisi, Özel Sayı: 80-84.
- Gönültaş, O., 2013. Doğu ladini (Picea orientalis) ve meşe (Quercus spp.) kabukları taneninin biotutkal üretiminde kullanılması. Doktora tezi, İstanbul Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul.
- Gönültaş, O., Uçar, M.B. 2018. Doğu ladini ve meşe kabuklarından tanen ekstraksiyon aşamasının optimize edilmesi. Türkiye Ormancılık Dergisi, 19(3): 323-329.
- Giurginca, M., Badea, N., Miu, L., Meghea, A., 2007. Spectral technics for identifying tanning agents in the heritage leather Items. Revista De Chimie-Bucharest-Original Edition, 58(9): 923-928.
- Hoong, Y.B., Paridah, M.D.T., Luqman, C.A., Koh, M.P., Loh, Y.F., 2009. Fortification of sulfited tannin from the Bark of Acacia mangium with phenol-formaldehyde for use as plywood adhesive. Industrial Crops and Products, 30: 416-421.
- Hu, R., Lin, L., Liu, T., Ouyang, P., He, B., Liu, S., 2008. Reducing sugar content in hemicellolose hydrolysate by DNS method: A revisit. Journal of Biobased Materials and Bioenergy, 2: 156-161.
- Ignat, I, Volf, I., Popa, V.I., 2011. Characterization of extractives from some raw materials processed by biorefining. COST Meeting, 25-26 January, Paris.
- Inoue, K. H., Hagerman, A. E., 1988. Determination of gallotannin with rhodanine. Analytical biochemistry, 169(2): 363-369.
- Khanbabaee, K., Ree, T.V., 2001. Tannins: Classification and definition. Natural Product Reports, 18: 641–649.
- Kim, S., 2003. Adhesion properties and curing behaviors of pine and wattle tannin-based adhesives, Thesis for The Degree of Master of Science, Seoul National University, Department of Forest Product Graduate School, Seul, North Korea.
- Kim, S., Kim, H. J., 2003. Curing behavior and viscoelastic properties of pine and wattle tannin-based adhesives studied by dynamic mechanical thermal analysis and FT-IR-ATR spectroscopy. Journal of adhesion science and technology, 17(10): 1369-1383.
- Laghi, L., Parpinello, G.P., Rio, D.D., Calani, L., Mattioli, A.U., Versari, A., 2010. Fingerprint of enological tannins by multiple techniques approach. Food Chemistry, 121: 783–788.
- Lee, W.J., Lan, W.C., 2006. Properties of resorcinol-tannin-formaldehyde copolymer resins prepared from the bark Extracts of Taiwan acacia and China fir. Bioresource Technology, 97: 257-264.
- Leyser, E., 1990. The formulation and commercialization of glulam pine tannin adhesives in Chile. Holz als Roh- und Werkstoff, 48: 25-29.
- Liiri, O., Sairanen, H., Kilpelainen, H., Kivisto, A., 1982. Bark extractives from Spruce as constitutes of plywood bonding agents. Holz als Roh- und Werkstoff, 40: 51-60.
- Miller, G.L., 1959. Use of DNS reagent for determination of reducing sugars. Analytical Chemistry, 31: 426-438.
- Ooa, C.W., Kassima, M.J., Pizzi, A., 2009. Characterization and performance of Rhizophora apiculata mangrove polyflavonoid tannins in the adsorption of copper (II) and lead (II). Industrial Crops and Products, 30: 152–161.
- Özacar, M., Soykan, C., Sengil, İ.A., 2006. Studies on synthesis, characterization, and metal adsorption of mimosa and valonia tannin resins. Journal of Applied Polymer Science, 102: 786–797.
- Pena, C., Larranaga, M., Gabilondo, N., Tejado, A., Echeverria, M., Mondragon, I., 2006. Synthesis and characterization of phenolic novolacs modified by chesnut and mimosa tannin extracts. Journal of Applied Polymer Science, 100: 4412-4419.
- Ping, L., Pizzi, A., Guo, Z.D., Brosse, N., 2012. Condensed tannins from grape pomace: Characterization by FTIR and MALDI TOF and production of environment friendly wood adhesive. Industrial Crops and Products, 40: 13– 20.
- Pizzi, A., 1983. Wood Adhesives Chemistry and Technology. Marcel Dekker: New York, vol. 1, 0-8247-1579-9.
- Pizzi, A., Leyser, E.P., Valenzuela, J., Clark, J.G., 1993. The chemistry and development of pine tannin adhesives for exterior particleboard. Holzforschung, 47: 168-174.
- Pizzi, A., 1994. Advanced Wood Adhesives Technology. Marcel Dekker Inc., New York, 978-0824-7926-64.
- Pizzi, A., Stephanou, A., 1994. Fast vs. slow-reacting non-modified tannin extracts for exterior particleboard adhesives. Holz als Roh- und Werkstoff, 52: 218-222.
- Pizzi, A., Mittal, K.L., 2003. Handbook of Adhesive Technology. Second Edition, Revised and Expanded, Marcel Dekker, New York, 0-8247-0986-1.
- Puica, N.M., Pui, A., Florescu, M., 2006. FTIR spectroscopy for the analysis of vegetable tanned ancient leather. European Journal of Science and Theology, 2(4): 49-53.
- Roffael, E., Dix, B., Okum, J., 2000. Use of spruce tannin as a binder in particleboards and medium density fiberboards (MDF). Holz als Roh- und Werkstoff, 301-305.
- Roux, D.G., 1951. Photometric method of tannins analysis for black wattle tannins. Journal of the Society of Leather Trade Chemists, 35: 322.
- Scalbert, A., Haslam, E., 1987. Polyphenols and chemical defence of the leaves of Quercus robur. Phytochemistry, 26: 3191-3195.
- Singleton, V.L., Rossi, J.A., 1965. Colorimetry of total phenolics with phosphomolybdicphosphotungstic acid reagents. American Journal of Enology and Viticulture, 16: 144-158.
- Valenzula, J., Leyser, E.V., Pizzi, A., Westermeyer, C., Gorrini, B., 2012. Industrial Production of Pine Tannin-Bonded Particleboard and MDF. European Journal of Wood and Wood Products, 70: 735–740.
- Vazquez, G., Antorrena, G., Gonzalez, J., Alvarez, J.C., 1996. Tannin-based adhesives for bonding high-moisture Eucalyptus veneers: Influence of tannin extraction and press conditions. Holz als Roh- und Werkstoff, 54: 93-97.
- Vazquez, G., Alverez, J.G., Freire, S., Suevos, F.L., Antorrena, G., 2001. Characteristics of Pinus pinaster bark extracts obtained under various extraction conditions. Holz als Roh- und Werkstoff, 59: 451.
- Vazquez, G., Alvarez, J.G., Suevos, F.L., Antorrena, G., 2002. Rheology of tannin-added phenol formaldehyde adhesives for plywood. Holz als Roh- und Werkstoff, 60: 88-91.
- Vazquez, G., Alvarez, J.G., Santos, J., Freire, M.S., Antorrena, G., 2009. Evaluation of potential applications for chesnut (Castanea sativa) shell and eucalyptus (Eucalyptus globus) bark extracts. Industrial Crops and Products, 29, 364-370.
- Yazaki, Y., Hillis, W.E., 1977. Polyphenolic extractives of Pinus radiata bark. Holzforschung, 31(1): 20-25.
- Yazaki, Y., Collins, P.J., 1994. Wood adhesives from Pinus radiata bark. Holz als Roh- und Werkstoff, 52: 185-190.
- Yurtsever, M., Şengil, İ.A., 2012. Adsorption and desorption behavior of silver ions onto valonia tannin resin. Transactions Nonferrous Metals Society of China, 22: 2846-2854.
Toplam 51 adet kaynakça vardır.
Ayrıntılar
| Birincil Dil | Türkçe |
|---|---|
| Konular | Mühendislik |
| Bölüm | Orijinal Araştırma Makalesi |
| Yazarlar | |
| Proje Numarası | T-22881 |
| Yayımlanma Tarihi | 27 Aralık 2019 |
| Kabul Tarihi | 13 Aralık 2019 |
| Yayımlandığı Sayı | Yıl 2019 Cilt: 20 Sayı: 4 |
