Abstract

It has been described the development of electrochemical nano sensor for the detection of mercury ions from aqueous solutions based on the formation of polyaniline nanoparticle films. Screen printed carbon electrodes were modified with polyaniline nanoparticles. Electropolymerization of polyaniline nanoparticles was performed by the pulsed potentiostatic method. The sample of polyaniline nanoparticles was prepared by repeating the potential step process three times. Structural and morploigcal characterization of polyaniline nanoparticles modified screen printed carbon electrode was performed using Fourier Transmission infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). PANI nanoparticles were spherical shaped having an apparent dimeter varying from 20 to 45 nm. Square wave anodic stripping voltammetry was used for the detection of Hg(II) on PANI NPs modified screen printed carbon electrode under optimized conditions. Hg(II) was deposited for 60 seconds by the reduction of Hg(II) in buffer solution:(citric acid and sodium chloride pH 2.30), followed by Hg stripping between 0.3 and 0.8 V at the following parameters: Scan rate: 100 mV s-1, frequency: 60 Hz, amplitude: 0.025 V and increment: 4.0 mV. it was found that the PANI NPs modified screen printed carbon electrode had a highest anodic stripping peak current in solution of pH 2.30. The limit of detection value for Hg(II) was found to be 2.50 ± 0.03 ppb. The limits of detections determined are below the corresponding guideline value from the World Health Organization (WHO). In addition, the modified nano electrode exhibited excellent reproducibility and high stability. The developed method was successfully applied to determine Hg(II) in real water samples with satisfactory results.

This paper presents a study of two commercial hollow-cathode lamps (HCLs) with the intention of demonstrating different phenomena in gas discharges. The optogalvanic effect in both HCLs is produced by a laser diode radiated at the wavelength that corresponds to neon transition 1s2–2p2 at 659.89 nm. The voltage–current characteristics of the lamps are explained using a classical theory of hollow-cathode discharge, while the optogalvanic signal is treated as a small perturbation of the discharge current. For certain values of voltage self-sustained current oscillations are observed in one of the HCLs. In the same HCL laser-induced optogalvanic dumped oscillations are detected. A phenomenological model that includes the effective circuit parameters of the discharge is used to explain the oscillation characteristics.

This study highlights the mechanism of formation for Bentonite clay surface properties. It investigates specific gravity and the influence of physicochemical characteristics on clay stability of structural forces on adsorbed water molecules. In particular, it describes the chemical composition, as well as cation exchange capacity (CEC). Bentonite clay is collected from the Murzuq city located 1150 km south of Tripoli i.e. southernmost town of Libya. The CEC value is leached by 500ppm Ca+2 at pH=8 equaled 84.5 mmoles/kg. While at pH=2, the value is (20.5 mmoles/kg). The leaching process is carried out by 500ppm K+ using flame emission photometer. The CEC value at pH =8 for sample is 91.5 mmoles/kg. Also the specific gravity is found to be 2.597. This value is in agreement with the obtained standard values for Wyoming (USA). The % MxOy of the clay is calculated by gravimetric method as follows: SiO2, 53.75; Al2O3, 21.46; Fe2O3, 1.4;CaO, 0.97; MgO, 2.13, and agreed with the XRF analysis as follows: SiO2, 54.93; Al2O3, 21.46; Fe2O3, 1.71; MgO, 3.18 ; CaO, 0.81; Na2O, 5.48; K2O, 0.54; TiO2,0.32. The results are adequately approximate and reasonable for both methods. The percent is very limited for trace elements Pb, Cr, Cd, Cu, Fe, and Zn. In the sample, it is about 0.21%. The result of XRD analysis (intensities) for sample is presented as follows: 50% quartz, 50% kaolinite, 5% Analcine, 7.5% Illite, 5% Natrolite, 10% Nontronite, 7% Montmorillonite. The formula calculation depends on the purity of clay and consequently the structural formula for Libyan Bentonite is: K0.094Na1.45Ca0.118 (Al2.92Fe0.175Ti0.033Mg0.646)VI( Al0.52Si7.48 …

The present research was implemented to analyses the seedling tolerance of three species Eucalyptus gomphocephala DC (Myrtaceae) (common name 'Tuart'), Eucalyptus marginata Sm. (common name 'Jarrah') and Corymbia calophylla (Lindl.) K.D. Hill & J. A. S. Johnson (common name 'Marri') to soil-induced stressor, namely soil alkalinity (limestone). Seeds germinated in shallow trays filled with white sand in a naturally lit glasshouse (control treatment). A liming treatment was conducted with 20% w/w crushed and sifted Tomala limestone adds to potting mix to increase soil pH. The experiment was conducted over 82 days. E. gomphocephala is restricted soils overlying limestone on study area and according to total seedling dry weight data and calculated relative growth rates coped best in a limestone-enriched soil. However, when examining all the growth and physiological data collected C. calophylla appeared to be the middling tolerant, with no significant difference in leaf allocation or leaf water loss between the well-watered controls and the limestone-enriched treatments whereas the E. marginata was the least tolerant with a 14% reduction in stomatal conductance. 

Abstract— With the growth of digital Arabic documents specially in information retrieval (IR) and natural language processing (NLP) applications, identification of irregular plurals which are commonly called broken plurals (BP) in modern standard Arabic becomes very urgent issue. Broken plurals are formed by imposing interdigitating patterns on stems, and singular words cannot be recovered by standard affix stripping stemming techniques. Identifying broken plurals is an important and difficult problem which needs to be addressed. In information retrieval, deriving singulars from plurals is referred to as a stemming. The process of stemming can be achieved by removing the attached affixes from a given word. To the best of our knowledge, all existing Arabic stemmers are unreliable and still under research. Consequently, this paper proposes an approach which identifies broken plurals without the need to perform the stemming process on any given word. The well known decision tree system (WEKA J48) is applied to build a classifier (model) on a very huge Arabic corpus as a training data which is pre-processed and prepared as a piece of this work. The built classifier is evaluated using unseen test set. The obtained results reveal that a very promising broken plural recognizer could be designed and implemented for NLP applications.

infected organs mainly liver and lungs and to some extent other organs including spleen, kidneys, heart, brain and bones of the animal carcasses. Prevention of cystic hydatid disease primarily focusing on veterinary investigations for controlling the extent and the intensity of echinococcosis in the definitive host populations, which indirectly may lead to control the prevalence of hydatid disease in the intermediate host animals. Treatment of cystic hydatidosis in livestock is still under investigation but anti-helminthes drugs can be used. Regular treatment, taking high degree of precautions when handling pets or dealing with animal meat must be taken into consideration to minimize the level of infection and egg excretion as well as the vaccination of ruminant intermediate hosts, are all in evaluation.

In this paper, we first recall the definition of a family of Koenig’s root-

finding algorithms known as Koenig’s algorithms (𝐾௣,௡) for polynomials. In the whole

paper p has degree 𝑑 ≥ 2 with real coefficients and real (and simple) zeros 𝑥௞ , 1 ≤

𝑘 ≤ 𝑑 .

Now we want to discuss Koenig’s algorithms in details where

𝑛 = 4, (𝐾௉,ସ(𝑧)).