If D = (V,A) is a digraph, its competition hypergraph CH(D) has the vertex set V and e ⊆ V is an edge of CH(D) iff |e| ≥ 2 and there is a vertex v ∈ V , such that e = {w ∈ V |(w, v) ∈ A}. We tackle the problem to minimize the number of strong components in D without changing the competition hypergraph CH(D). The results are closely related to the corresponding investigations for competition gra...

A cyclic q-partition of a hypergraph (V,E) is a partition of the edge set E of the form {F, F , F θ 2 , . . . , F θ q−1 } for some permutation θ of the vertex set V . Let Vn = {1, 2, . . . , n}. For a positive integer k, ( Vn k ) denotes the set of all k-subsets of Vn. For a nonempty subset K of Vn−1, we let K n denote the hypergraph ( Vn, ⋃ k∈K ( Vn k )) . In this paper, we find a necessary an...

In this paper, we define prime (semiprime) hyperideals and prime(semiprime) fuzzy hyperideals of semihypergroups. We characterize semihypergroupsin terms of their prime (semiprime) hyperideals and prime (semiprime)fuzzyh yperideals.

Thermodynamic effects play an important role in the cavitation dynamics of cryogenics fluids. Such flows are characterized by strong variations in fluid properties with the temperature. A compressible, multiphase, one-fluid solver was developed to study and to predict thermodynamic effects in cavitating flows. To close the system, a cavitation model is proposed to capture metastable behaviours ...

the studies carried out over 2010-13 involved a static field experiment initiated in 1999 at brody research station of the poznan university of life science, poland. the soil tillage systems for winter wheat were compared on a soil classified as albic luvisols. the aim of experiments was to evaluate impact of ploughless soil tillage on some soil physical, chemical, biological properties and win...

A field experiment was conducted to evaluate the yield and chemical composition of triticalegrain in different crop rotation and tillage systems. The first experimental factor was thecropping system – a) crop rotation and b) monoculture and the second factor was the tillagesystem – 1) conventional (CT), 2) reduced (RT) and 3) no-tillage (NT). The spring triticale yieldwas found to be 15.4% high...