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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Research Journal of Pharmacognosy
- نوع مقاله: Journal Article
- کلمات کلیدی: essential oil,Burseraceae,Octyl acetate,Boswellia carterii,gamma sterilization
- چکیده:
- چکیده انگلیسی: Background and objectives:Gamma-irradiation is used vastly for both decontamination and sterilization of natural products; but these high-energy rays can affect heat-sensitive essential oils.
Methods: The oleo-gum-resin of Boswellia carterii (Burseraceae) was sterilized by γ-irradiation at dose 30 KGy. The essential oils obtained by hydrodistillation of non-irradiated Boswellia (NIB) and irradiated Boswellia (IB) were analyzed by GC/MS and the changes were compared. The structure of octyl acetate as the major component and marker of B. carterii was confirmed by MS/MS.
Results: Twenty-five compounds comprising 99.55% of NIB oil and nineteen compounds comprising 98.61% of IB oil were identified. Major constituents which were common for both oils were octyl acetate (52.67 % in NIB, 76.51 % in IB), 1-octanol (6.37 % in NIB, 5.19 % in IB), duva-4, 8, 13-triene-1,3α diol (5.52 % in NIB, 3.94 % in IB), verticiol (13.63 % in NIB) and verticillane type diterpene (5.4 % in IB) they made up 78.19% and 91.04% of NIB and IB, respectively.
Conclusion: Gamma irradiation was an efficient method for sterilization of Boswellia carterii oleo-gum resin, but it resulted in change in the essential oil composition particularly octyl acetate changed from 52.67% to 76.51%.- انتشار مقاله: 06-02-1395
- نویسندگان: P. Badr,S. Daneshamouz,A.A. Mohammadi,A.R. Akbarizadeh,S. Afsharypuor
- مشاهده
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: The inventory system under consideration consists of one central warehouse and an arbitrary number of retailers controlled by a continuous review inventory policy (R,Q). Independent Poisson demands are assumed with constant transportation times for all retailers and a constant lead time for replenishing orders from an external supplier for the warehouse. Unsatisfied demands are assumed to be lost in the retailers and unsatisfied retailer orders are backordered in the warehouse. An approximate cost function is developed to find optimal reorder points for given batch sizes in all installations and the related accuracy is assessed through simulation.
- انتشار مقاله: 22-05-1385
- نویسندگان: M.R. Akbari Jokar,M.R. Akbari Jokar,M.R. Akbari Jokar
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Composite,FEM,Buckling analysis,Critical Lattice Structure,Rib (Stiffener)
- چکیده:
- چکیده انگلیسی: Due to their light weights and high load carrying capacities, composite structures are widely used in various industrial applications especially in aerospace industry. Stiffening ribs are the main features of lattice type composite structures. Strength to weight ratio is known to be as one of the most critical design parameter in these structures. In this study, the effect of some parameters such as the physical characteristics of the material, shell thickness, angle, thickness and number of ribs on distribution of stresses and buckling loads of shell are investigated. For this purpose, 3D finite element analysis using ANSYS software explicitly was done and then compared with experimental test results. Increasing the thickness of the outer shell causes the structural strength will rise to 50 percent. The next effective parameter is reduction of rib angle which provides an increase of 30 percent in specific load. Although Stiffenerrs (ribs) have a major role in load carrying, but increasing the rib number causes the structural weight rises, thus compared with the two previous parameters do not have a significant effect on the strength of structures
- انتشار مقاله: 09-10-1394
- نویسندگان: S.A. Latifi-rostami,R. Akbari Alashti,Amin Kolahdooz
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Mechanical Research and Application
- نوع مقاله: Journal Article
- کلمات کلیدی: Free vibration,Patch mass,Laminated Composite Plate,Refined plate theory
- چکیده:
- چکیده انگلیسی: The effect of a distributed patch mass on the natural frequency of vibration of a laminated rectangular plate with simply supported boundaries is investigated. The third order displacement field of a composite laminated rectangular plate is defined using the two variable refined plate theory. Equations of motion of the plate are obtained with the help of calculus of variation. Parametric study of non-dimensional natural frequencies of vibration is carried out and the effects of geometrical parameters such as the aspect ratio of the plate, size and location of the patch mass on these frequencies are studied. The results are then compared with those reported using the third order shear deformation theory. The results are found to be in very good agreement.
- انتشار مقاله: 17-03-1394
- نویسندگان: R. Akbari Alashti,R. Alibakhshi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Electrical and Computer Engineering Innovations (JECEI)
- نوع مقاله: Journal Article
- کلمات کلیدی: Automatic Bug assignment,Bug reports,Bug Clustering,Similarity criteria
- چکیده:
- چکیده انگلیسی: Background and Objectives: It is generally accepted that the highest cost in software development is associated with the software maintenance phase. In corrective maintenance, the main task is correcting the bugs found by the users. These bugs are submitted by the users to a Bug Tracking System (BTS). The bugs are evaluated by the bug triager and assigned to the developers to correct them. To find a related developer to correct the bug, recent developers’ activities and previous bug fixes must be examined. This paper presents an automated method to assign bugs to developers by identifying similarity between new bugs and previously reported bug reports.
Methods: For automatic bug assignment, four clustering techniques (i.e. Expectation-Maximization (EM), Farthest First, Hierarchical Clustering, and Simple Kmeans) are used where a tag is created for each cluster that indicates an associated developer for bug correction. To evaluate the quality of the proposed methods, the clusters generated by the methods are compared with the labels suggested by an expert triager.
Results: To evaluate the performance of the proposed method, we use real-world data of a large scale web-based system which is stored in the BTS of a software company. To select the appropriate algorithm for the clustering, the outputs of each clustering algorithm are compared to the labels suggested by the expert triager. The algorithm with closer output to the expert opinion is selected as the best algorithm. The results showed that EM and FarthestFirst clustering algorithms with 3% similarity error have the most similarity with the expert opinion.
Conclusion: the results obtained by the algorithms show that we can successfully apply them for bug assignment in real-world software development environments.
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Copyrights
©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.
======================================================================================================- انتشار مقاله: 16-06-1398
- نویسندگان: M. Yousefi,R. Akbari,S. M. R. Moosavi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mechanical Engineering Transactions of the ISME
- نوع مقاله: Journal Article
- کلمات کلیدی: Functionally Graded Material,Rotating Disk,thermoplastic analysis,variable material property theory
- چکیده:
- چکیده انگلیسی: This work presents thermoplastic analysis of FG rotating diskswith variable thickness and constant angular velocity. The solutions are obtained by variable material property (VMP) theory. In this theory, the domain is divided into some finite sub-domains in the radial direction, in which the properties are assumed to be constant and the form of the elastic response is used to solve elastic-plastic problems. The results are compared with the results obtained by the finite element analysis using ANSYS software. The results reveal that mentioned methods are in very good agreement in both thermoelastic and themroplastic states. Finally, the effect of various parameters including the thermal distribution and thickness profile on the stress behavior of disk are investigated.
- انتشار مقاله: 10-05-1392
- نویسندگان: E. Mahdavi,R. Akbari Alashti,A. Cheloee Darabi,M. Alizadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mechanical Engineering Transactions of the ISME
- نوع مقاله: Journal Article
- کلمات کلیدی: functionally graded materials,Hollow thick sphere,Polynomial differential quadrature,Thermo-elasticity
- چکیده:
- چکیده انگلیسی: Thermo-elastic analysis of a functionally graded hollow sphere is carried out and numerical solutions of displacement, stress and thermal fields are obtained using the Polynomial differential quadrature (PDQ) method. Material properties are assumed to be graded in the radial direction according to a power law function, however the Poisson’s ratio is assumed to be constant. The governing partial differential equations are obtained in terms of displacement and temperature fields and expressed in the form of series equations. A comparison of numerical results with the analytical and finite element results is presented that shows an excellent agreement. The effect of the material grading parameter, temperature variation and thickness of the sphere on the distribution of stress, radial displacement and temperature fields is investigated.
Thermo-elastic analysis of a functionally graded hollow sphere is carried out and numerical solutions of displacement, stress and thermal fields are obtained using the Polynomial differential quadrature (PDQ) method. Material properties are assumed to be graded in the radial direction according to a power law function, however the Poisson’s ratio is assumed to be constant. The governing partial differential equations are obtained in terms of displacement and temperature fields and expressed in the form of series equations. A comparison of numerical results with the analytical and finite element results is presented that shows an excellent agreement. The effect of the material grading parameter, temperature variation and thickness of the sphere on the distribution of stress, radial displacement and temperature fields is investigated.- انتشار مقاله: 12-01-1390
- نویسندگان: R. Akbari Alashti,M. Khorsand,M. H. Tarahhomi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Industrial Mathematics
- نوع مقاله: Journal Article
- کلمات کلیدی: Hepatitis B virus (HBV),Basic reproduction number ($R_0$),Gompound matrices,Global stability.
- چکیده:
- چکیده انگلیسی: Hepatitis B virus (HBV) infection is a major public health problem in the world today. A mathematical model is formulated to describe the spread of hepatitis B, which can be controlled by vaccination as well as treatment. We study the dynamical behavior of the system with fixed control for both vaccination and treatment. The results shows that the dynamics of the model is completely determined by the basic reproductive number R_0. if R_0<1, the disease-free equilibrium is globally asymptotically stable by using approach that given by Kamgang and Sallet. Then the authors prove that if R_0>1, the disease-free equilibrium is unstable and the disease is uniformly persistent. Furthermore, If R_0>1, the unique endemic equilibrium is globally asymptotically stable by using a generalization of the Poincar e-Bendixson criterion.
- انتشار مقاله: 25-11-1394
- نویسندگان: R. Akbari,A. Vahidian Kamyad,A. A. Heydari,A. Heydari
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Brucella melitensis,Omp25,BLS,Bioinformatics analysis,Recombinant vaccine
- چکیده:
- چکیده انگلیسی: Brucellosis is a well-known infection in domestic animals which caused by Brucella bacterium. Due to
serious economic and medical consequences of this disease, various efforts have been made to prevent the
infection through the use of recombinant vaccines based on Brucella outer membrane protein (OMP)
antigens. The objectives of the present study were cloning, sequencing and epitope prediction of Omp25
and BLS genes as two major Brucella melitensis antigens. The full-length open reading frame (ORF) of
Omp25 and BLS genes were amplified and cloned into pTZ57R/T vector. Phylogenetic analysis of
sequenced genes showed that both genes were nearly similar in different Brucella species. Several online
prediction softwares were used to predict B and T-cells epitopes, secondary and tertiary structures,
antigenicity ability and enzymatic degradation sites. Bioinformatic tools used in the current study were
confirmed by the results of three different experimental epitope predictions. Bioinformatic analysis
identified five and two B-cell and two and one T-cell epitopes for Omp25 and BLS antigens, respectively.
Finally, according to the antigenicity ability and proteosomal recognition site common B and T-cell epitope
was predicted for Omp25 (154-162 amino acids) and BLS (37-48 and 119-139 amino acids). Results of this
study might be useful for recombinant vaccine development.- انتشار مقاله: 05-06-1393
- نویسندگان: M. Tahmoorespur,M.H. Sekhavati,S. Yousefi,T. Abbassi-Daloii,M. Azghandi,R. Akbari
- مشاهده