dust particles have dangerous impacts on human health, the environment, and the economy. recently dust storms, originating from arabian countries, have increased remarkably, affecting western and central parts of iran.hysplit model and the mean monthly maps of aai (absorbing aerosol index), surface skin temperature, and top soil layer moisture from omi (ozone measurement instrument) have been u...

Carpal fractures excluding the scaphoid can cause morbidity that is disproportionate to their incidence because they are easily overlooked and are often harbingers of a wider wrist injury. Failure to recognize a more global injury pattern can result in undertreatment and permanent wrist dysfunction. Diagnosis requires a high index of suspicion, familiarity with carpal topography to guide the ph...

Given two graphs, G and H, we say that H is an induced subgraph of G if V (H) ⊆ V (G), and two vertices of H are adjacent if and only if they are adjacent in G. Let F be a (possibly infinite) family of graphs. A graph G is called F -free if no member of F is isomorphic to an induced subgraph of G. A clique in a graph is a set of vertices all pairwise adjacent, and a stable set is a set of verti...

The Erdős-Hajnal conjecture states that for every graph H, there exists a constant δ(H) > 0, such that if a graph G has no induced subgraph isomorphic to H, then G contains a clique or a stable set of size at least |V (G)|. This conjecture is still open. We consider a variant of the conjecture, where instead of excluding H as an induced subgraph, both H and H are excluded. We prove this modifie...

There are sixteen 3-connected graphs on eleven or fewer edges. For each of these graphs H we discuss the structure of graphs that do not contain a minor isomorphic to H.

For a graph G and a set of graphs H, we say that G is H-free if no induced subgraph of G is isomorphic to a member of H. Given an integer P > 0, a graph G, and a set of graphs F , we say that G admits an (F , P )-partition if the vertex set of G can be partitioned into P subsets X1, . . . ,XP , so that for every i ∈ {1, . . . , P}, either |Xi| = 1, or the subgraph of G induced by Xi is {F}-free...

For each infinite cardinal k we give several necessary and sufficient conditions for a graph not to contain a minor isomorphic to the infinite kbranching tree in terms of a certain kind of a "tree-decomposition," in terms of a "path-decomposition," and also in terms of a "cops-and-robber game." We also give necessary and sufficient conditions for a graph not to contain a subgraph isomorphic to ...

in this research, the spatial distribution of electrical conductivity and ph of springs, ghanats and the base flow concentration places on the streams of central and south-west and central parts of the hamedan-bahar plain were evaluated. using different geostatistical methods such as kriging, minimum curvature, inverse distance, natural neighbor, local polynomial and radial basis functions, 108...

the trend of changes in water quality plain eyvanakey to manage shared water resources is necessary semnan and tehranprovince.for this purpose after determining the study range in the eyvanekey area, field investigation was performed to identify the geological formations and the distribution there of as well as the faults and salt domes locations using existing geological maps. afterwards throu...