Background: Echinophora platyloba DC (Apiaceae) is one of the two endemic species of Echinophora genus in Iran. It has many folkloric uses and several biological activities but there is no information about its phytoconstituents. Objective: In this work some of the secondary metabolites were isolated, purified and identified from n-hexane, ethyl acetate and methanol extracts from the aerial pa...

In this manuscript, we describe the synthesis of the carbohydrazide 2. Acid-catalyzed condensation with several carbonyl compounds to afford the corresponding carbohydrazide derivatives 3-12. Their acetylation afforded the corresponding acetyl derivatives 13-22. Oxidative cyclization of O-acetyl derivatives 19-22 afforded the corresponding 1,3,4-oxadiazole derivatives 23-2...

Osteomyelitis of the vertebral body is a rare condition, and its prognostic is reserved in several species, caus- ing spinal cord involvement, and neurological manifestations. In foals, the disease can be resulted from an infection caused by several bacteria, in which R. equi has a higher incidence among the responsible agents. The objective of this report is to describe the osteomyelitis occur...

in recent year, the evolutionary structural optimization (eso) method, has been applied as an effective tool for structures design. the concept of eso method is to use the finite element  results in each iteration of process and removal of inefficient material based on these results. in this method there are several experimental parameters such as rejection rate and evolutionary rate that are e...

In this paper, a computationally simple approach for damage localization and quantification in beam-like structures is proposed. This method is based on using modal flexibility curvature (MFC) and particle swarm optimization (PSO) algorithm. Analytical studies in the literature have shown that changes in the modal flexibility curvature can be considered as a sensitive and suitable criterion for...

Cylindrical liquid storage tanks are considered as vital structures in industrial complex whose nonlinear dynamic behavior is of crucial importance. Some of these structures around the world have demonstrated poor seismic behavior over the last decades. There are several methods and techniques for rehabilitation and reducing damages in these structures which among them passive control devices, ...

In this study, to enhance the optimization process, especially in the structural engineering field two well-known algorithms are merged together in order to achieve an improved hybrid algorithm. These two algorithms are Teaching-Learning Based Optimization (TLBO) and Harmony Search (HS) which have been used by most researchers in varied fields of science. The hybridized algorithm is called A Di...

Following T. H. Chan, we consider the problem of approximation of a given rational fraction a/q by sums of several rational fractions a1/q1, . . . , an/qn with smaller denominators. We show that in the special cases of n = 3 and n = 4 and certain admissible ranges for the denominators q1, . . . , qn, one can improve a result of T. H. Chan by using a different approach. 2000 Mathematics Subject ...