the aim of this study was to develop an extended-release tablet formulation using a new in situ cross-linking method. the effects of polyvalent cations on theophylline release from tablets made with the polyanionic polymers sodium alginate and sodium carboxymethylcellulose, were investigated. different miliequivalents of the di and tri-valent cation, ca2+ and al3+, were added to tablet formulat...

abstract with increasing population, mine activities for metal proceeding are also increasing, so environment will be influenced by contaminant especially heavy metals. in situ immobilization of heavy metals using inexpensive amendments is considered as a simple and cost-effective approach for reducing heavy metal contamination. in this research we used sequential extraction for assessing reduc...

The thorough description of the peculiarities of additively manufactured (AM) structures represents a current challenge for aspiring freeform fabrication methods, such as selective laser melting (SLM). These methods have an immense advantage in the fast fabrication (no special tooling or moulds required) of components, geometrical flexibility in their design, and efficiency when only small quan...

A novel method based on selective laser sintering (SLS) process is proposed for the first time to prepare complex and high-performance carbon fibres/polyamide12/epoxy (CF/PA12/EP) ternary composites. The procedures are briefly described as follows: prepare polyamide12 (PA12) coated carbon fibre (CF) composite powder; build porous green parts by SLS; infiltrate the green parts with high-performa...

Abstract: In recent years deadly earthquakes in seismic areas have caused special concerns regarding liquefaction phenomenon by researchers and specialists. Excess pore water pressure in loose sediments may cause phenomena such as boiling, shearing strength and dynamic stiffness reduction and lateral movements cause difficulties. Many remedial methods such as soil replacement with proper materi...

A literature review revealed that most of the empirical equations introduced for determination of the uniaxial compressive strength (UCS) of rocks based on the Schmidt hammer rebound number (N) are not sufficiently reliable mostly due to the relatively low coefficient of correlations. This is attributed to the fact that in most cases one formula is used for all types of rocks, altho...

Concrete strength evaluated from compression tests on cores is affected by several factors causing differences from the in-situ strength at the location from which the core specimen was extracted. Among the factors, there is the damage possibly occurring during the drilling phase that generally leads to underestimate the actual in-situ strength. In order to quantify this effect, in this study t...