HYDRATION AND PROPERTIES OF BLENDED CEMENT SYSTEMS INCORPORATING INDUSTRIAL WASTES

This paper aims to study the characteristics of ternary blended system, namely granulated blast-furnace slag (WCS), from iron steel company and Homra (GCB) from Misr Brick (Helwan, Egypt) and silica fume (SF) at 30 mass % pozzolanas and 70 mass % OPC. The required water of standard consistency and setting times were measured as well as physico-chemical and mechanical characteristics of the hardened cement pastes were investigated. Some selected cement pastes were tested by TGA, DTA and FT-IR techniques to investigate the variation of hydrated products of blended cements. The pozzolanic activity of SF is higher than GCB and WCS. The higher activity of SF is mainly due to its higher surface area than the other two pozzolanic materials. On the other side, GCB is more pozzolanic than WCS due to GCB containing crystalline silica quartz in addition to an amorphous phase. The silica quartz acts as nucleating agents which accelerate the rate of hydration in addition to its amorphous phase, which can react with liberating Ca(OH)2 forming additional hydration products

Reduction of secondary lobes in joint angle and delay estimation in angle of arrival localization to detect MAC address spoofing in wireless networks

in this paper, we solve the problem of  secondary lobes that are due to noise that comes from constructive and destructive multipath interference that are resulted in received signal strength (RSS) variation over time. This is to develop a very efficient localization algorithm that uses a unique fingerprint angle of arrivals (AOAs), in a specified range, with associated time delays (TDs), in the surrounded sparsity design promoting multipath parameter (i.e:RSS). We solve this problem to detect physical identity spoofing of nodes in radio wireless networks, and localize adversaries and jammers of wireless networks. All radio waves are vulnerable to many types of attacks due to the ability to capture them and sniff or eavesdropping on them in the open space. Physical identity spoofing is used to launch many types of attacks against wireless networks like Denial of Service (DOS), Man-In-The-Middle and Session Hijacking and eavesdropping. Eavesdropping is a human-based social engineering attack. Active adversaries are able to jam and eavesdrop simultaneously, while passive adversaries can only eavesdrop on passed signals. In TCP/IP protocol for example, Media Access Card (MAC) Address is transferred in 802.11 frames. Detection process was carried out by analyzing electromagnetic radio waves that are used to transfer data, in the form of radio wave signals that are formed by the modulation process which mixes the electromagnetic wave, with another one of different frequency or amplitude to produce the signal with a specified pattern of frequency and amplitude. We depended on the angle of arrival of vectors and time delay across scattered areas in the surrounded space to solve the problem of co-location in detection and localization of jammers. We used Maximum Likelihood (ML) angle of arrival determination because ML approaches, known to their higher accuracy and enhanced resolution capabilities. And we assessed their computational complexity that was considered as the major drawback for designers to their implementation in practice.   Our solution was tested on a jammer that changed the signal strength of received signal at the receiver at an angle of arrival 30 degree. And we used scatterers density to determine the angle of arrival of the sender. The simulation has observed that the power of the received signal has changed from the range of angles 20 to 40 degrees. We used scatterers because they describe the density of the signal power, and also enhance the signal to noise ratio, that resulted from the multipath fading of the signal strength. And also overcoming the problem of secondary lobes that are due to signal propagation, while determining the angle of arrival of a signal sender. So, we developed a new passive technique to detect MAC address spoofing based on angle of arrival localization. And assessed the computation complexity of the localization technique through depending on a range angle to estimate the angle of arrival of the adversary within it. And we reduced number of secondary lobes, and their peaks, in the importance function, while determining the angle of arrival, and so increasing the accuracy of angle of arrival measurement. We compared our work to other techniques and find that our technique is better than these techniques

EXTRACTIVE SPECTROPHOTOMETRIC DETERMINATION OF SOME ANTIHISTAMINIC DRUGS FROM PHARMACEUTICAL FORMULATIONS USING ROSE BENGAL

Objective: Simple and sensitive an extractive-spectrophotometric method have been developed for the determination of four important antihistaminic drugs, namely desloratadine (DSL), chlorpheniramine maleate (CPM), diphenhydramine hydrochloride (DPH) and fexofenadine (FXO).Methods: This method is based on the formation of colored ion-pair complexes between the basic nitrogen of the drugs and halofluorescein dyes, namely rose bengal (RB) dye in weak acidic medium. The formed complexes were extracted with dichloromethane measured spectrophotometrically at 550 nm.Results: The reaction conditions were optimized to obtain the maximum color intensity. Beer's law was obeyed with a good correlation coefficient (0.9963-0.9975) in the concentration ranges 1-6, 4-18, 6-16 and 2-22 µg/ml for DSL, CPM, DPH and FXO, respectively. The composition ratio of the ion-pair complexes was found to be 1:1 as established by Job's method.Conclusion: The proposed method was successfully extended to pharmaceutical preparations. Excipients used as additive in commercial formulations did not interfere in the analysis. The proposed method can be recommended for quality control and routine analysis where time, cost effectiveness and high specificity of analytical technique are of great importance.Â

UTILIZATION OF ION-PAIR COMPLEX FORMATION FOR THE SPECTROPHOTOMETRIC DETERMINATION OF SOME ANTIDEPRESSANT DRUGS IN PHARMACEUTICAL FORMULATIONS

Objective: A new, simple and sensitive spectrophotometric method has been developed for the determination of some antidepressant drugs, namely desvenlafaxine (DSV), dapoxetine (DAP) and citalopram (CIT) in pharmaceutical formulations.Methods: The proposed method was based on the formation of yellow colored ion-pair complex between the studied drugs and two sulphonphthalein dyes viz., bromophenol blue (BPB), and bromothymol blue (BTB) in acidic medium. The optimizations of the reaction conditions were investigated. Beer's law limits, Sandell's sensitivity, correlation coefficient, detection, and quantification limits were calculated.Results: The formed complexes showed absorption maxima at 412 nm and 410 nm measured for all the drugs with BPB and BTB, respectively. The Job's method of continuous variations indicated that a single l: l ion-pair complex was formed. Calibration curves were linear over the concentration range of 0.8–11.4, 0.8–6.4 and 0.8–8.0 μg/ml for DSV, DAP and CIT, respectively.Conclusion: The proposed method has been applied successfully for the analysis of the investigated drugs in pure and in their dosage forms. No interference was observed from common excipients present in pharmaceutical formulations. The proposed method is suitable for quality control applications.Keywords: Desvenlafaxine, Dapoxetine, Citalopram, Sulphonphthalein dyes, Extraction spectrophotometry, Pharmaceutical formulation

Kinetics and physico-chemical properties of alkali activated blast-furnace slag/basalt pastes

AbstractGranulated blast-furnace slag (GBFS) is a by-product of the metallurgical industry and consists mainly of lime and calcium–magnesium aluminosilicates that defined as the glassy granular material formed by rapid cooling of molten slag with excess water resulting in an amorphous structure. Alkali-activated slag (AAS) binders have taken a great interest from researchers due to its manufacturing process which has important benefits from the point of view of the lower energy requirements and lower emission of greenhouse gases with respect to the manufacturing of Portland cement. In this study, GBFS was replaced by 20, 40 and 60wt.% of basalt activated by 6wt.% of alkali mixture composed of 1:1 sodium hydroxide (SH) and liquid sodium silicate (LSS) mixed with sea water and cured in 100% relative humidity up to 90days. The physic-chemical parameters were studied by determination of setting time, combined water content, bulk density and compressive strength. As the amount of basalt increases the setting time as well as compressive strength decreases while the bulk density increases. The compressive strength values of dried pastes are greater than those of saturated pastes. The hydrated products are identified by TGA/DTG analysis, IR spectroscopy and scanning electron microscopy (SEM)

EXTRACTION-SPECTROPHOTOMETRIC DETERMINATION OF SOME ANTIHYPERTENSIVE DRUGS IN PHARMACEUTICAL AND BIOLOGICAL FLUIDS USING TWO SULPHONPHTHALEIN DYES

Objective: Two simple and sensitive extractive spectrophotometric methods have been described for the determination of some antihypertensive drugs namely, bisoprolol (BIS), carvedilol (CAR), propranolol (PRP) and telmisartan (TLM) either in pharmaceutical formulations or biological fluids. Methods: The proposed methods involve the formation of yellow colored ion-pair complexes of the studied drugs with two sulphonphthalein dyes as bromophenol blue (BPB) and bromocresol purple (BCP) in acidic medium. Results: The colored products are extracted into methylene chloride and measured spectrophotometrically at 402 nm for all the drugs. Beer's law limits, Sandell sensitivity values, limits of detection (LOD) and quantification (LOQ) values have also been reported for both the methods. The composition of the ion-pair complexes was found 1: 1 by Jobʼs continuous variations method. The effects of concentration of dye, pH and interference of excipients have been studied and optimized. The accuracy and precision of the methods were evaluated on intra-day and inter-day basis; the relative standard deviation (RSD) was<1.72%. Various analytical parameters have been evaluated and the results have been validated by statistical data and indicated no significant difference in accuracy and precision. Conclusion: The proposed methods were successfully applied to the determination of the studied drugs in pharmaceutical formulations and in biological fluids. Keywords: Antihypertensive drugs, Sulphonphthalein dyes, Ion-pair, Pharmaceuticals

CHARGE-TRANSFER COMPLEXES OF CHLORPHENOXAMINE HYDROCHLORIDE WITH CHLORANILIC ACID, 2,3-DICHLORO-5,6-DICYANO-1,4-BENZOQUINONE AND 7,7,8,8-TETRACYANOQUINODIMETHANE AS π-ACCEPTORS

Objective: To develop simplified, accurate and precise visible spectrophotometric strategies for the assay of chlorphenoxamine hydrochloride (CPX) in pure drug and in its pharmaceutical preparations. Methods: The described methods depended on the formation of charge-transfer (CT) complexes of intense color between CPX as donor with three π-acceptors, chloranilic acid (CLA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the colored reaction products were estimated spectrophotometrically at 520 nm, 460 nm and 840 nm for CLA, DDQ, and TCNQ complexes, individually. All the optimum conditions were established. The proposed methods were validated in term of linearity, limit of detection as per the international conference on harmonization guidelines ICH Q2 (R1). Results: The complexes obeyed Beer’s law in the concentration range of 16-144, 6-54 and 4-76 μg/mlwith molar absorptivity at 0.30×104, 0.68×104 and 0.58×104 l/mol/cm for CLA, DDQ, and TCNQ, individually. According to Benesi-Hildebrand plots, the association constants and changes of standard free energy were determined. 1:1 was the ratio of composition of the formed CT-complex. Conclusion: The obtained results revealed that the developed method can be applied successfully for the determination of CPX in drug formulations samples with good accuracy and precision

EXTRACTIVE-SPECTROPHOTOMETRIC DETERMINATION OF SOME ANTIMUSCARINIC ANTAGONIST IN TABLET FORMULATIONS USING ERIOCHROME CYANINE R

Objective: To develop and validate simple, rapid and sensitive spectrophotometric method for the assay of four antimuscarinic antagonists, namely oxybutynin (OXB), solifenacin (SOL), tolterodine (TOL) and fesoterodine (FES) in bulk and pharmaceutical formulations.Methods: The proposed method is based on the reaction of the selected drugs with eriochrome cyanine R (ECR) in buffered aqueous solution at pH 1.0. The formed ion-pair complexes were extracted with dichloromethane and measured quantitatively with maximum absorption at 464 nm. All variables that affect on color intensity such as pH, buffer volume and concentration of ECR and extractive solvents were studied and optimized.Results: The calibration graphs were linear over the concentration range of 4–24, 4–32, 4–32 and 2–22 mg/ml for OXB, SOL, TOL and FES, respectively. The stoichiometry of the reaction was found to be 1:1 in all cases. Molar absorptivity values were found to be 2.043×104, 1.856×104, 1.798×104 and 2.856×104 l/mol/cm for OXB, SOL, TOL and FES, respectively. Excipients which used as an additive in commercial formulations did not interfere in the analysis.Conclusion: The developed method was successfully applied to determine OXB, SOL, TOL and FES in pharmaceutical preparations. The developed method can be used for quality control and routine analysis where time, cost effectiveness and high specificity of analytical technique are of great importance

Influence of some chemicals and solvents on the lytic activity and the adsorption of bacteriophages on Pectobacterium carotovoroum Subsp. carotovorum

Recently, bacteriophages have been used to control hazardous bacterial soft rot disease on crops. However, agricultural plants are frequently treated with different chemicals (fertilizers, pesticides and solvents), so we assessed the effect of some commonly used chemicals and solvents on the lytic activity of tested bacteriophages and their adsorption potential. This study reports the isolation of three specific phages against the Pectobacterium carotovorum subsp. carotovorum DSM 30170 strain, designated as ?PC1, ?PC2 and ?PC3, then partially characterized using electron microscopy and genome size. The 3 isolated phages belong to the Myoviridae family. The results obtained were based on the plaque-forming unit observed after incubation. By increasing the chemical concentrations (from 0.1 to 0.5 mM), calcium chloride (CaCl2) and potassium chloride (KCl) showed a significant increase in the lytic activity of the phages. Copper sulphate (CuSO4) and copper chloride (CuCl2) showed a substantial decrease in the activity of ?PC3; however, such a decrease was insignificant for ?PC1 and ?PC2. By increasing the solvent concentrations (from 30 % v/v to 70 % v/v), propanol, ethanol and methanol showed a significant decrease in the count of the three isolated phages, ?PC1, ?PC2 and ?PC3, compared to the control. Chloroform was the only solvent that did not reduce the phage titer. Our findings offer significant information for developing a strategy to combat the P. carotovorum subsp. carotovorum caused bacterial soft rot disease. avoiding copper compounds and alcoholic solvents such as propanol, ethanol and methanol in plots where phages are applied seems advisable