Naturally occurring carbonation of cement-based materials is a slow phenomenon. Many factors control the rate of carbonation process in cement-based products. A comprehensive knowledge of the major factors controlling the rate of carbonation, and their effects on the properties of the materials subjected to it, is necessary for using this technology for CO2 sequestration. Most of the studies re...

Abstract: The performance of corroded reinforced concrete (RC) beams strengthened with externally bonded carbon fiber reinforced polymer (CFRP) materials may be affected by a weak interface caused either by defective bonding between the new and old concrete in the case of cover replacement or by expansive cracks in the case of direct application. To investigate this effect, thirteen strengthene...

In the coal mining industrial environment, the materials of RC bunkers suffer from serious aging problems. The cracking and deterioration of concrete and the corrosion of steel reinforcement lead to a degeneration of structural performance and a decline of structural reliability. In this paper, based on on-site detection and coal mining ground industrial environment, the deterioration character...

We describe a noncommutative deformation theory for presheaves and sheaves of modules that generalizes the commutative deformation theory of these global algebraic structures, and the noncommutative deformation theory of modules over algebras due to Laudal. In the first part of the paper, we describe a noncommutative deformation functor for presheaves of modules on a small category, and an obst...

A fertile area of recent research has demonstrated concrete polynomial time lower bounds for natural hard problems on restricted computational models. Among these problems are Satisfiability, Vertex Cover, Hamilton Path, MOD6-SAT, Majority-of-Majority-SAT, and Tautologies, to name a few. The proofs of these lower bounds follow a proof-by-contradiction strategy that we call resource-trading or a...

A fertile area of recent research has demonstrated concrete polynomial time lower bounds for solving natural hard problems on restricted computational models. Among these problems are Satisfiability, Vertex Cover, Hamilton Path, MOD6-SAT, Majority-ofMajority-SAT, and Tautologies, to name a few. The proofs of these lower bounds follow a certain proof-by-contradiction strategy that we call altern...

background: in megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. the use of high-density concrete decreases the required thickness of the concrete barrier hence, its disadvantage is its high cost. in a nuclear reactor, neutron radiation is the most difficult to shield. a method for p...

Surfaces of carbon fibre roving were modified by means of a low temperature plasma treatment to improve their bonding with mineral fines; the latter serving as an inorganic fibre coating for the improved mechanical performance of carbon reinforcement in concrete matrices. Variation of the plasma conditions, such as gas composition and treatment time, was accomplished to establish polar groups o...

The paper gives an overview on the meta-data specification for administrating and enforcing enterprisewide security for heterogeneous and distributed information systems. The meta-data serves as a basis to maintain enterprise-wide security information centrally, to integrate isolated security specifications, to keep the consistency between different security policies, and to perform access cont...