The primary task of technologists-designers is to optimize the structure and properties building composite materials. Its achievement allows simultaneously increasing their efficiency, reliability durability. article presents results determining granulometric composition a gypsum binder (CGB) by computational experimental modeling using known equations "ideal" curves. Due fact that when designi...

This study was designed to evaluate the detrimental effect of atrazine (ATR) on germinal epitheliums (GE) cytoplasmic carbohydrate (CH) and unsaturated fatty acids (UFA) ratio and to clarify the effect of ATR on serum levels of FSH, LH, testosterone and inhibin-B (INH-B). The impact of ATR exposure on total antioxidant capacity (TAC), sperm DNA packing and integrity were also investigated. Seve...

‎In this paper we take $mathcal A$ to be the category {bf Pos-S}‎ ‎of $S$-posets‎, ‎for a posemigroup $S$‎, ${mathcal M}_{pd}$ to‎ ‎be the class of partially ordered sequantially-dense‎ ‎monomorphisms and study the categorical properties‎, ‎such as‎ ‎limits and colimits‎, ‎of this class‎. ‎These properties are usually‎ ‎needed to study the homological notions‎, ‎such as injectivity‎, ‎of‎ ‎$S$-...

We discuss experiments on dense packing of granular beads that are cyclically sheared quasi-statically between parallel walls under constant pressure boundary conditions. The particle positions inside the shear cell are tracked over several cycles in three dimensions using particle index-matching imaging technique. The total volume fraction of the particles φ in the cell is observed to increase...

This paper addresses the equal circle packing problem, and proposes an efficient Quasi-physical Quasi-human (QPQH) algorithm. QPQH is based on a modified Broyden-Fletcher-GoldfarbShanno (BFGS) algorithm which we call the local BFGS and a new basin hopping strategy based on a Chinese idiom: alternate tension with relaxation. Starting from a random initial layout, we apply the local BFGS algorith...

The retention of nanocrystallinity in dense ceramic materials is still a challenge, even with the application of external pressure during sintering. The compaction behavior of high purity and acetate enriched zinc oxide (ZnO) nano-powders was investigated. It was found that acetate in combination with water plays a key role during the compaction into green bodies at moderate temperatures. Appli...

For a subset A of a Polish group G, we study the (almost) packing index indP (A) (resp. IndP (A)) of A, equal to the supremum of cardinalities |S| of subsets S ⊂ G such that the family of shifts {xA}x∈S is (almost) disjoint (in the sense that |xA ∩ yA| < |A| for any distinct points x, y ∈ S). Subsets A ⊂ G with small (almost) packing index are small in a geometric sense. We show that indP (A) ∈...

Yb2O3 is an efficient sintering additive for enhancing not only thermal conductivity but also the high-temperature mechanical properties of Si3N4 ceramics. Here we report the fabrication of dense Si3N4 ceramics with high thermal conductivity by the gas pressure sintering of α-Si3N4 powder compacts, using only Yb2O3 as an additive, at 1900 °C under a nitrogen pressure of 1 MPa. The effects of Yb...

DNA exhibits a surprising multiplicity of structures when it is packed into dense aggregates. It undergoes various polymorphous transitions (e.g., from the B to A form) and mesomorphous transformations (from hexagonal to orthorhombic or monoclinic packing, changes in the mutual alignment of nearest neighbors, etc). In this report we show that such phenomena may have their origin in the specific...

Crystals of 4-chloro-2'-biphenylol grown at 263 K and studied at both 293 and 142 K are loosely packed and contain OH.O bonded tetramers composed of four crystallographically independent molecules (Z' = 4). Approximate symmetry relationships between independent molecules are apparent in many, perhaps even most, structures with Z' > 1, but are not obvious in this structure. The inefficient cryst...