We investigate the complexity of enumerating pseudo-intents in the lectic order. We look at the following decision problem: Given a formal context and a set of n pseudo-intents determine whether they are the lectically first n pseudo-intents. We show that this problem is coNPhard. We thereby show that there cannot be an algorithm with a good theoretical complexity for enumerating pseudo-intents...

in this work, the adsorption of the anionic dye, congo red (cr), from aqueous solution by using tea waste (tw) has been carried out at 30 °c. the equilibrium sorption isotherms and kinetics were investigated. the equilibrium adsorption was studied by the langmuir and freundlich models of adsorption. the experimental results manifested that the langmuir isotherm was the best model for the adsorp...

Background: Synthetic dyes are serious pollutants and wide ranges of methods have been employed for their removal from aquatic systems. We studied the adsorption of "Nile blue A" (NBA), an anionic dye, from aqueous solution by oxidized multi-walled carbon nanotubes (MWCNTs). Methods: Scanning electron microscope and Fourier transform infrared spectroscopy were used to characterize ...

A stability indicating High-Performance Liquid Chromatography (HPLC) method wasvalidated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidativeconditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mMKH2PO4 and acetonitrile (60:40 v/v, pH = 3.5) was used as the mobile phase. The method waslinear over the range of 1-20 μg/mL of ce...

Graphene, a new member of the carbon family, was used as an adsorbent due to its exceptional capability to remove Rhodamine B (RB) and Malachite Green (MG), two organic dyes, from aqueous solutions. Adsorption kinetics of RB and MG onto graphene and adsorption capacity of the adsorbent were studied. Also the effects of parameters, including pH, contact time, temperature, and adsorbent dosag...

In this work, adsorption kinetics were investigated in order to remove the acid blue 62 off the aqueous solutions using mesoporous silicate SBA-15 loaded with tannic acid (tannin-SBA-15). Nitrogen adsorption and desorption test (BET), X-ray diffraction (XRD) and Fourier transform infra-red spectroscopy (FT-IR) analysis characterize synthesized composite. The impacts of some parameters such as P...

A stability indicating High-Performance Liquid Chromatography (HPLC) method wasvalidated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidativeconditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mMKH2PO4 and acetonitrile (60:40 v/v, pH = 3.5) was used as the mobile phase. The method waslinear over the range of 1-20 μg/mL of ce...

The electrocoagulation (EC) is a simple and efficient method for the treatment of many water and wastewaters.The kinetics of decolorization of Acid Yellow 23 by EC using iron electrodes was studied. Theelectrodecolorization rate follows pseudo-first order kinetic with respect to the AY23 concentration havingkapp= 5.65 cm min-1 at T= 295 K. The rate equation is as follows:ln [AY23]t – ln [AY23]0...

The paper starts with an examination and critique of Tarski’s wellknown proposed explication of the notion of logical operation in the type structure over a given domain of individuals as one which is invariant with respect to arbitrary permutations of the domain. The class of such operations has been characterized by McGee as exactly those definable in the language L∞,∞. Also characterized sim...

We propose a simple but powerful approach to the verification of parameterised systems. The approach is based on modelling the reachability between parameterized states as deducibility between suitable encodings of states by formulae of first-order predicate logic. To establish a safety property, that is non-reachability of unsafe states, the finite model finder is used to find a finite counter...