Turkish Journal of Agriculture and Forestry (TURK J AGRIC FOR)

Publications in this journal

• Article: Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation Method and Determination of the Thermal Stability of Its Lyophilized Form

  Emin Selahattin UMDU, Seyhun GEMİLİ, Sacide Alsoy ALTINKAYA, Nilgün YAPRAK, Ahmet YEMENİCİOĞLU, Çisem MECİTOĞLU GÜÇBİLMEZ, Fatma IŞIK ÜSTOK, Fatih Yalçın Güneş YENER
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  ABSTRACT: Lysozyme was partially purified from hen egg white by precipitation of non-lysozyme protein impurities during incubation in the presence of ethanol. The thermal stability of the obtained partially purified enzyme was also characterized. The incubation of diluted egg white for 2-8 h in the presence of 20% ethanol was not very effective for the partial purification of lysozyme by precipitation of major egg white proteins; however, 4- to 6-h or 6- to 8-h incubation of diluted egg white in the presence of 30% and 40% ethanol could be employed more effectively for partial purification of lysozyme. Without applying the incubation period, the highest specific activity was obtained by the treatment of egg white with 40% ethanol. Thus, ethanol at this concentration could be used for a continuous process of partial purification. For batch lysozyme purification, on the other hand, incubation in the presence of 30% ethanol was more appropriate. The activities and protein contents of dialyzed and lyophilized enzymes obtained by 6 h-incubation in the presence of 20%, 30%, and 40% ethanol precipitations were 1878, 6669, and 6115 U/mg powder, and 0.98, 0.90, and 0.93 mg protein per mg powder, respectively. The ranges of thermal inactivation parameters, such as D (D80 °C = 29.2-59 min, D90 °C = 8.8-21 min) and z (z80-90 °C = 17.4-22.3 °C) values of the enzyme, clearly indicated the moderate and variable heat stability of lyophilized lysozymes obtained from different batches of egg white.
  Turkish Journal of Agriculture and Forestry 02/2013; 31(2):125-134.
• Article: Possibilities for reducing the tractor engine friction losses at cold start using ultrasonic irradiation technique

  Florin MARIASIU
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  ABSTRACT: Challenges to the effectiveness of specific activities and production technologies in agriculture appear more pressing today as every day worldwide demand for agricultural products increases. Mechanization of agriculture brings positive quantitative and qualitative effects, but the process of continuous modernization of production tools (tractors and agricultural machinery) needs to be directly linked to increasing economic efficiency in their use. Increasing life expectancy and period of use of agricultural tractors can be achieved by reducing the friction and wear that occurs between the relative moving mechanical parts. A special case is the cold start process of compression ignition engines, when large forces develop and the lack of lubricating oil film can lead to damage of the engine components. This paper proposes the use of an ultrasound emitter device, which manages minimum energy consumption, to modify the rheological properties of engine oil lubrication to reduce the friction losses. Results obtained from laboratory experiments, were processed in a computer simulation of the tractor diesel engine cold start process. The losses due to the internal friction of the engine components were comparatively analyzed (obtaining the percentage lower friction losses by ultrasonic conditioning of lubrication oil). It was found that the proposed method offers benefits in terms of rational use and can prolong engine life, with positive effects on the economic efficiency of agricultural processes.
  Turkish Journal of Agriculture and Forestry 01/2013;
• Article: Auxetic springs for seating

  Smardzewski J
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  ABSTRACT: It is commonly believed that furniture spring systems are far more durable and friendly in utilisation than foam systems. The aim of this research project was to design and realise models of individual auxetic compression springs and, additionally, to determine their resistance to cyclic as well as prolonged static loads. The study was conducted using numerical calculations and verification of the results by laboratory experiments. The results of the performed investigations made it possible to conclude that the designed spring was characterised by stiffness characteristics similar to the compression characteristics of polyurethane foams. Cyclical and prolonged static loadings haven't significant influence on changes in spring heights, so their impact on the comfort of seating is insignificant. New construction of spring guaranteed auxetic properties of systems made up of many parallel-joined systems of springs. Due to such properties, seats designed using auxetic springs can exhibit high comfort in comparison with traditional systems made of wire springs or foams.
  Turkish Journal of Agriculture and Forestry 01/2013; 37.
• Article: Arbuscular mycorrhizal fungi associated with tree peony in three geographic locations of China

  Shi Z, Chen Y, Hou X, GAO S, Wang F
  Turkish Journal of Agriculture and Forestry 01/2013;
• Article: Withdrawal force capacity of mortise and loose tenon T-type furniture joints

  Derikvand M, Smardzewski J, Ebrahimi G, Dalvand M, Maleki S
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  ABSTRACT: The main goal of this study was to determine the effect of wood species and loose tenon length on the withdrawal force capacity of M&LT T-type furniture joints. The specimens were manufactured from six different wood species, whereas the tenon species was selected from oriental beech. The length of the tenon was determined on the basis of the length of its gluing into the horizontal member of the joint. The above-mentioned length in the presented study amounted to: 10, 20 and 30 mm. It was found, on the basis of the obtained research results, that joints manufactured from beech were characterised by the highest withdrawal force capacity; on the other hand, this trait was the lowest in the case of joints made from the light wood of poplar and fir. The gluing in length of the tenon exerted a significant influence on the withdrawal force capacity of the joints. The greatest withdrawal force capacity increment of M&LT T-type joints was obtained when the tenon length changed from 10 to 20 mm.
  Turkish Journal of Agriculture and Forestry 01/2013; 37:1-8.
• Article: Determination of the impact of creeping of furniture joints on their rigidity

  Smardzewski J, Kłos R, Fabisiak B
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  ABSTRACT: The study presents research results on the effect of creeping on changes in the rigidity of selected joints used in constructions of upholstered furniture expressed as the substitute modulus of elasticity Ez. The modulus was calculated analytically using for this purpose Maxwell-Mohr constitutive equation. In addition, actual runs of creeping curves were determined and a theoretical model well describing the obtained results was selected. Simultaneously, detailed statistical analysis was carried out. It was found that creeping exerted a significant impact on the mechanical quality of the examined joints by reducing their substitute modulus of elasticity by 11-16%. This modulus can be employed in numerical calculations using the finite elements method.
  Turkish Journal of Agriculture and Forestry 01/2013; 38.
• Article: Rootstock potential of Turkish Lagenaria siceraria germplasm for watermelon: plant growth, yield and quality

  KARACA FATIH, YETISIR HALIT, SOLMAZ ILKNUR, CANDIR, KURT, SARI, GULER
  Turkish Journal of Agriculture and Forestry 01/2012; 36(2):167-177.
• Article: Research on antifungal and inhibitory eff ects of DL-limonene on some yeasts

  Ünal. M. Ü, Uçan, Şener, A. and Dinçer
  Turkish Journal of Agriculture and Forestry 01/2012; 36:576.
• Article: Tufenkci S., Demir S., Sensoy S., Ünsal H., Demirer E., Erdinç C., Biçer Ş., Ekincialp A. 2012. Effects of arbuscular mycorrhizal fungi on seedling growth of four hybrid cucumber (Cucumis sativus L.) cultivars. Turkish Journal of Agriculture and Forestry. 36: 317-327.

  Tufenci, Demir, Sensoy, Ünsal, Demirer, Erdinc, Bicer, Ekincialp
  Turkish Journal of Agriculture and Forestry 01/2012; 36(3):317-327.
• Article: Production of Cellulase by Pleurotus ostreatus and Pleurotus sajor-caju in Solid State Fermentation of Lignocellulosic Biomass

  Khalil MI, Hoque MM, BasuniaMA, Alam N, Khan MA
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  ABSTRACT: Bioconversion of cellulosic components into fermentable sugars has currently been accomplished with the help of the microbial enzyme, cellulase. In this study, Pleurotus ostreatus (Jacquin ex Fr.) Kummer and Pleurotus sajor-caju (Fr.) Singer were tested for cellulase production by solid state fermentation (SSF) using saw dust, sugarcane bagasse, and paddy straw as substrate. To enhance production, the substrates were pretreated with 1% and 4% NaOH solutions. Supernatants of extracted enzyme solutions were used to estimate reducing sugar and soluble protein, as well as enzyme activities. Maximum production of reducing sugar and soluble protein were recorded in 12 and 10 day fermented products, respectively. In the production of reducing sugars, P. ostreatus (42.8 mg g-1) was found to be more efficient than P. sajor-caju (10.9 mg g-1), while P. sajor-caju was more efficient in soluble protein production (40.2 mg g-1) compared to P. ostreatus (3.1 mg g-1). P. ostreatus was found to be more efficient in the individual components of cellulase enzyme production than P. sajor-caju. All the enzyme activities were found to attain a peak at 10 days of fermentation. The highest activities of endoglucanase, exoglucanase, and b-glucosidase were recorded as 7.08, 7.36, and 3.60 units (µmole of glucose released/min/g substrate), respectively, for P. ostreatus, while that of P. sajor-caju were 1.9, 2.03, and 2.63 units, respectively. Total cellulase activity was found to reach a maximum at 10 days of fermentation for both strains. For P. ostreatus it was recorded as 3.51 units, while for P. sajor-caju it was 0.82 units. This study suggests P. ostreatus as an important source of cellulase enzymes.
  Turkish Journal of Agriculture and Forestry 01/2011; 35:333-341.
• Article: Induction of variability through mutagenesis in opium poppy (Papaver somniferum L.)

  Chatterjee A, Shulka S, Mishra BK, Rastogi A, Singh SP
  Turkish Journal of Agriculture and Forestry 01/2011; 35:1-11.
• Article: Heritability for some agronomic characters of rice (Oryza sativa L.) and their linked microsatellites identification

  Amiri Fahliani R, M. Khodambashi, S. Houshmand, A. Arzani, K. Sorkheh
  Turkish Journal of Agriculture and Forestry 01/2011; 35:481-490.