Kestane kabuğu, ısırgan otu, kivi meyvesi ve narenciye özütlerinin antioksidan potansiyelleri ve bazı balık patojenlerine karşı antibakteriyel etkileri

The use of antioxidants and antibacterial compounds obtained from natural sources is important for human and animal health, as well as for controlling diseases. The aim of this study was to evaluates the antioxidant potentials and antibacterial effects of water extracts of C. sativa, U. dioica, A. deliciosa and C. aurantium against selected Gram-negative (Vibrio harveyi, Vibrio vulnificus, Vibrio anguillarum, Vibrio rotiferianus, Vibrio campbellii, Vibrio ponticus and Aeromonas veronii) and Gram-positive (Bacillus thuringiensis) bacteria. Results of antioxidant test indicated that the chestnut shell extract had the highest DPPH inhibition (87.03 %) followed by citrus fruit (80.40 %). All extracts showed antibacterial activity against one or more species of bacteria. The most susceptible bacteria were V. harveyi (32.05 mm zone diameter) and V. campbellii (21.66 mm zone diameter) and the resistant species were V. anguillarum, V. ponticus and A. veronii. The results show that plant extracts have the potential to be used as an antibacterial agent in aquaculture and as an antioxidant agent in processing technology.Doğal kaynaklardan elde edilen antioksidan ve antimikrobiyal bileşiklerin kullanımı, insan ve hayvan sağlığı için olduğu kadar hastalıkların kontrolü açısından da önemlidir. Bu çalışmanın amacı, C. sativa, U. dioica, A. deliciosa ve C. aurantium bitkilerinden elde edilen su bazlı özütlerin antioksidan potansiyellerinin belirlenmesi, aynı zamanda seçilen Gram-negatif (Vibrio harveyi, Vibrio vulnificus, Vibrio anguillarum, Vibrio rotiferianus, Vibrio campbellii, Vibrio ponticus ve Aeromonas veronii) ve Gram-pozitif (Bacillus thuringiensis) bakterilere karşı antibakteriyel etkilerinin değerlendirilmesidir. Antioksidan aktivitesi testi sonuçlarına göre, en yüksek DPPH inhibisyonu (%87,03) kestane kabuğu özütünde, ikinci olarak turunç özütünde (%80,40) belirlenmiştir. Tüm özütlerin bir veya daha fazla bakteri türüne karşı antibakteriyel aktivite gösterdiği tespit edilmiştir. Özütlere karşı en duyarlı bakteriler V. harveyi (32,05 mm zon çapı) ve V. campbellii (21,66 mm zon çapı), dirençli türler ise V. anguillarum, V. ponticus ve A. veronii olarak belirlenmiştir. Çalışma sonuçları, elde edilen özütlerin su ürünleri yetiştiriciliğinde antibakteriyel madde ve işleme teknolojisinde antioksidan ajan olarak kullanılma potansiyeline sahip olduğunu göstermektedi

Analyzing the contact problem of a functionally graded layer resting on an elastic half plane with theory of elasticity, finite element method and multilayer perceptron

This paper presents a comparative study of analytical method, finite element method (FEM) and Multilayer Perceptron (MLP) for analysis of a contact problem. The problem consists of a functionally graded (FG) layer resting on a half plane and pressed with distributed load from the top. Firstly, analytical solution of the problem is obtained by using theory of elasticity and integral transform techniques. The problem is reduced a system of integral equation in which the contact pressure are unknown functions. The numerical solution of the integral equation was carried out with Gauss-Jacobi integration formulation. Secondly, finite element model of the problem is constituted using ANSYS software and the two-dimensional analysis of the problem is carried out. The results show that contact areas and the contact stresses obtained from FEM provide boundary conditions of the problem as well as analytical results. Thirdly, the contact problem has been extended based on the MLP. The MLP with three-layer was used to calculate the contact distances. Material properties and loading states were created by giving examples of different values were used at the training and test stages of MLP. Program code was rewritten in C++. As a result, average deviation values such as 0.375 and 1.465 was obtained for FEM and MLP respectively. The contact areas and contact stresses obtained from FEM and MLP are very close to results obtained from analytical method. Finally, this study provides evidence that there is a good agreement between three methods and the stiffness parameters has an important effect on the contact stresses and contact areas

Suture button fixation method used in the treatment of syndesmosis injury: A biomechanical analysis of the effect of the placement of the button on the distal tibiofibular joint in the mid-stance phase with finite elements method

Purpose: The purpose of this study is to research the effect of suture button (SB) fixation, a method used at the treatment of ankle syndesmosis injury, which was applied in various angles, pretension force, and levels, on the distal tibiofibular joint (DTFJ) in the mid-stance phase, with the help of three-dimensional finite elements method (FEM)Method: The ankle of a healthy individual was digitally analyzed by a finite element method-based package computer program. Then, anterior inferior tibiofibular ligament (AITFL), interosseous ligament, posterior inferior tibiofibular ligament (PITFL) and deltoid ligament (DL) were cut and force and rotation has been applied to the proximal tibia, resulting in syndesmosis injury. Then, various suture button applications on the injured model have been analyzed. Three parameters have been changed; which were divergence in the axial plane ( 20 degrees, 30 degrees, 40 degrees), distance from the ankle ( 2, 3, 4 cm ), and pretension force ( 20 0, 30 0, 60 0 N )Results: As the result of this study, the rotation, change in the gap between the distal tibia and distal fibula, and the displacements of the fibula in the x and y axes have been obtained, and numerical results were evaluated. As the force increased, rotation, change in the gap between the distal tibia and distal fibula, and the displacements of the fibula decreased. As suture button application rotation increased, change in the gap between the distal tibia and distal fibula, and displacements of the fibula increased. As the distance from the ankle increases and reaches a certain level, the results converge to those of the healthy model; in the proximal, it diverges from healthy results.Conclusion: In the study, it has been shown that abnormal tibiofibular joint movements can be prevented with suture button application, and optimum application parameters (divergence in the axial plane, distance from the ankle, and pretension force) are given for proper reduction.(c) 2022 Elsevier Ltd. All rights reserved

Assessment of different solution methods for receding contact problems in functionally graded layered mediums

This paper presents a comparative study of different methods, such as the analytical method, finite element method (FEM), and multilayer perceptron (MLP) for analyzing a frictionless receding contact problem. The problem consists of two layers resting on a Winkler foundation. The top layer is functionally graded (FG) along the depth and pressed using a rigid cylindrical stamp, whereas the bottom layer is homogeneous. We assumed that the contact between the two layers, and that between the FG layer and the rigid cylindrical stamp are frictionless; additionally, compressive normal tractions can be transmitted through the interface. First, the problem was solved analytically using the theory of elasticity and integral transform techniques. Second, the finite element solution of the problem was obtained using ANSYS software. Finally, the problem was extended based on the MLP, which an artificial neural network used for different problem parameters. The results of this study showed that the variations in the contact lengths at the interface between the rigid cylindrical stamp and the FG layer, those between the homogeneous layer and the FG layer, and the maximum contact pressures at these interfaces depended on various dimensionless quantities such as the stamp radius, stiffness parameter, shear modulus ratio, and elastic spring constant ratio. We observed that the results obtained with the three different methods, namely the analytical method, FEM, and MLP, are extremely compatible with each other, thus proving the accuracy of these results

Antioxidant Potential of Chestnut Shell, Stinging Nettle, Kiwi Fruit and Citrus Fruit Extracts and Antimicrobial Effects Against Some Fish Pathogens

The use of antioxidants and antibacterial compounds obtained from natural sources is important for human and animal health, as well as for controlling diseases. The aim of this study was to evaluates the antioxidant potentials and antibacterial effects of water extracts of C. sativa, U. dioica, A. deliciosa and C. aurantium against selected Gram-negative (Vibrio harveyi, Vibrio vulnificus, Vibrio anguillarum, Vibrio rotiferianus, Vibrio campbellii, Vibrio ponticus and Aeromonas veronii) and Gram-positive (Bacillus thuringiensis) bacteria. Results of antioxidant test indicated that the chestnut shell extract had the highest DPPH inhibition (87.03 %) followed by citrus fruit (80.40 %). All extracts showed antibacterial activity against one or more species of bacteria. The most susceptible bacteria were V. harveyi (32.05 mm zone diameter) and V. campbellii (21.66 mm zone diameter) and the resistant species were V. anguillarum, V. ponticus and A. veronii. The results show that plant extracts have the potential to be used as an antibacterial agent in aquaculture and as an antioxidant agent in processing technology.Doğal kaynaklardan elde edilen antioksidan ve antimikrobiyal bileşiklerin kullanımı, insan ve hayvan sağlığı için olduğu kadar hastalıkların kontrolü açısından da önemlidir. Bu çalışmanın amacı, C. sativa, U. dioica, A. deliciosa ve C. aurantium bitkilerinden elde edilen su bazlı özütlerin antioksidan potansiyellerinin belirlenmesi, aynı zamanda seçilen Gram-negatif (Vibrio harveyi, Vibrio vulnificus, Vibrio anguillarum, Vibrio rotiferianus, Vibrio campbellii, Vibrio ponticus ve Aeromonas veronii) ve Gram-pozitif (Bacillus thuringiensis) bakterilere karşı antibakteriyel etkilerinin değerlendirilmesidir. Antioksidan aktivitesi testi sonuçlarına göre, en yüksek DPPH inhibisyonu (%87,03) kestane kabuğu özütünde, ikinci olarak turunç özütünde (%80,40) belirlenmiştir. Tüm özütlerin bir veya daha fazla bakteri türüne karşı antibakteriyel aktivite gösterdiği tespit edilmiştir. Özütlere karşı en duyarlı bakteriler V. harveyi (32,05 mm zon çapı) ve V. campbellii (21,66 mm zon çapı), dirençli türler ise V. anguillarum, V. ponticus ve A. veronii olarak belirlenmiştir. Çalışma sonuçları, elde edilen özütlerin su ürünleri yetiştiriciliğinde antibakteriyel madde ve işleme teknolojisinde antioksidan ajan olarak kullanılma potansiyeline sahip olduğunu göstermektedi

Evaluation of the contact problem of functionally graded layer resting on rigid foundation pressed via rigid punch by analytical and numerical (FEM and MLP) methods

In this paper, frictionless contact problem for a functionally graded (FG) layer is considered. The FG layer is subjected to load with a rigid punch and the FG layer is bonded on a rigid foundation. Analysis of this contact problem was carried out by analytical method, finite element method (FEM) and multilayer perceptron (MLP), comparatively. The main target of this study is to investigate the applicability of MLP analysis for frictionless contact problem of FG layer bonded on a rigid foundation. Analytical solution of the problem is based on the theory of elasticity and integral transform techniques. The physical contact problem is transformed to mathematical system of integral equation. The integral equation in which the contact pressures are unknown functions is numerically solved with the Gauss-Jacobi integration formulation. Finite element analysis of the problem is carried out with ANSYS software by using the two-dimensional modeling technique. Finally, MLP analysis has been used to obtain the contact distances of the problem. Three-layer MLP was used for this calculation. Material properties and loading conditions were created by giving examples of different values in MLP training and testing stages. Program code was rewritten in C++. As a result, average deviation values such as 1.67 and 0.885 were obtained for FEM and MLP, respectively. It has been determined that the contact areas and contact stresses obtained from FEM and MLP are quite compatible with the results obtained from the analytical method

On the plane receding contact between two functionally graded layers using computational, finite element and artificial neural network methods

The frictionless double receding contact problem for two functionally graded (FG) layers pressed by a uniformly distributed load is addressed in this paper. The gradation in the layers is assumed to follow an exponential variation through the height with constant Poisson's ratios. The lower layer rests on a homogeneous half-plane (HP). There is no adhesion between the FG layers or between the lower layer and the HP. The body forces of the FG layers and HP are ignored. First, the governing equations are reduced to a system of two singular integral equations with contact pressures and contact lengths as unknowns using Fourier transform techniques and boundary conditions. The integral equations are solved numerically using the Gauss-Chebyshev integration formula. Then, a parametric finite element analysis is performed using the augmented contact method. Finally, the problem was extended based on the multilayer perceptron (MLP), an artificial neural network used for different problem parameters. The effects of stiffness parameters, the normalized load length, the ratio of shear moduli, the ratio of FG layer heights to the normalized contact lengths, and normalized maximum contact pressures are explored. The results of finite element analysis and the MLP approach are used to validate the normalized maximum contact pressures and contact lengths obtained from an analytical method based on elasticity theory, and finally, good agreement between these three methods results is obtained. The obtained results could help in designing multibody indentation systems with FGMs

Application of artificial neural networks in the analysis of the continuous contact problem

This paper investigates the artificial neural network (ANN) to predict the dimensionless parameters for contact pressures and contact lengths under the rigid punch, the initial separation loads, and the initial separation distances of a contact problem. The problem consisted of two elastic infinitely layers (EL) loaded by means of a rigid cylindrical punch and resting on a half-infinite plane (HP). Firstly, the problem was formulated and solved theoretically using the Theory of Elasticity (ET). Secondly, the contact problem was extended based on the ANN. External load, the radius of punch, layer heights, and material properties were created by giving examples of different values used at the training and test stages of ANN. Finally, the accuracy of the trained neural networks for the case was tested using 134 new data, generated via ET solutions to determine the best network model. ANN results were compared with ET results, and well agreements were achieved

The contact problem of the functionally graded layer resting on rigid foundation pressed via rigid punch

The solution of contact problems is extremely important as we encounter many situations involving such problems in our daily lives. One of the most important parameters effective in solving contact problems is the materials of the parts in contact. While it is relatively easy to solve the contact mechanics of the systems created with traditional materials with a homogeneous microstructure and mechanical distribution, it may be more difficult to solve the contact problem of new generation materials that do not show a homogeneous distribution. As a result of this situation, it is seen that studies on contact problems of materials that do not exhibit such a homogeneous internal structure and mechanical properties are extremely limited in the literature. In this context, in this study, analytical and numerical analyzes of a contact problem created using functionally graded materials were carried out and the results were evaluated mutually. It has been decided that the contact areas and contact pressures acquired from numerical method are reasonably appropriate with the results obtained from the analytical method

Finite element analysis of the mechanical behavior of the different angle hip femoral stem

Femoral stems with proximal metaphyseal involvement are commonly used total hip replacement components with very good results. In this study, total hip arthroplasty (THA) application was analyzed using a three-dimensionally modeled human hip joint by finiite element method. The aim of the study is to investigate the effects of changes in the direction of the femoral stem on these complications. Finite element analysis is performed on a model of femur bone by varying the femur angles. Finite element models were prepared for three different positions (5 degrees varus, neutral, 5 degrees valgus) on the femur without cement during walking motions. A sinusoid dynamic load with amplitude between 300 N and 1700 N and with a frequency of 1 Hz was applied. The stresses, strains and deformations that occurred on the femur and stems were determined at the end of the finite element analysis and compared to each other. Considering the results of strain, strain and deformation in the study, it is seen that the closest results to the natural load bearing of the femur are in the valgus position. The results obtained in the neutral position are also close to these results. In the metaphyseal points involving the femur stem, the highest values were found in the varus position. In all three positions, the femoral stem provides the transfer of the load from the proximal femur. The lowest stress, strain and deformation results were obtained in the valgus position, especially in the metaphyseal where the prosthesis is involved. It is seen that there are values close to this in the neutral position. This situation may be thought to result in a decrease in the proximal stress shield, an increase in bone protection compared to the varus position, a long-term loosening and a decrease in periprosthetic fracture