Insecticidal properties of whole meal or protein extracts of the bean seeds Phaseolus vulgaris L. on juvenile stages of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

Callosobruchus maculatus is a pest that causes serious damage to Cicer arietinum (chickpea) stored seeds, but that does not develop in seeds of other legumes such as Phaseolus vulgaris or Pisum sativum. The bean seed is rich in antinutritional compounds known to inhibit the development of C. maculatus. In an integrated approach to protect stocks of Cicer arietinum against attacks of this weevil, this study had the main objective to assess the potential of using bean flours from a wild bean Vigna caracalla, four varieties of P. vulgaris, and of a crude extract from P. vulgaris lectins seed. The extraction method was chosen to extract lectin-like protein compounds. The biological effects of bean flour or protein extracts were observed on artificial seeds composed from C. arietinum flour enriched with P. vulgaris whole flour or extracts incorporated at different percentages. The antinutritional activity either of bean-seed whole meal or of lectin-like extracts was determined by the analysis of different biological parameters. Incorporation of bean flour mixed with chickpeas decreased fertility and fecundity of female C. maculatus and caused longer development times of juvenile stages. Peptide extracts of the P. vulgaris reduced fecundity and survival of C. maculatus. Keywords: Callosobruchus maculatus, Phaseolus vulgaris, Lectin-like extract, Insecticidal properties, Artificial see

Gain Enhancement of Monopole Antenna using AMC Surface

A CPW rectangular-ring antenna over an Artificial Magnetic Conductor (AMC) is presented in this work. The AMC is a designed as a dual-band structure having an array of unit cells and operates at 2.45GHz and 5.20 GHz. A CPW antenna uses this dual-band AMC structures as a back-plane. Performance comparison is carried out with and without incorporation of AMC. The simulated and measured results show that the combination of the AMC reflector and the antenna provide directional properties at both frequency bands. It has been found that the antenna gain increases by about 5 dB

Miniaturized Concentric Hexagonal Fractal Rings Based Monopole Antenna for WLAN/WiMAX Application

In this paper a new antenna design technique is introduced in order to achieve tri-band operation as well as antenna miniaturization. The technique consists of using two concentric first-iterative hexagonal rings connected to each other as a radiating patch fed with a Y-shaped microstrip line. The proposed antenna operates at three frequency bands to cover 2.4/5.8 GHz WLAN and 3.5GHz WiMAX bands. The numerical analysis and simulation are carried out with CST MWS. The measured return losses of the proposed antenna show good performance and good agreement with the simulated results. Consequently the proposed antenna with compact size of 9.77 mm x 17 mm x 1.63 mm is well suited for wireless applications

Design and Fabrication of a Novel Quadruple-Band Monopole Antenna Using a U-DGS and Open-Loop-Ring Resonators

In this Article, a novel quadruple-band microstrip patch antenna is proposed for the systems operating at quad-band applications. The antenna structure is composed of modified rectangular patch antenna with a U-shaped defected ground structure (DGS) unit and two parasitic elements (open-loop-ring resonators) to serve as a coupling-bridge. The proposed antenna with a total size of 31×33 mm2 is fabricated and tested. The measured result indicates that the designed antenna has impedance bandwidths for 10 dB return loss reach about 180 MHz (4.4–4.58 GHz), 200 MHz (5.4–5.6 GHz), 1100 MHz (7.2–8.3 GHz), and 700 MHz (9.6–10.3 GHz), which meet the requirements of the wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX), C and X bands applications. Good agreement is obtained between measurement and simulation results

A Compact Multi-Band Monopole Antenna using Metamaterial for WLAN/WiMAX Applications

In this paper, a tri-band printed monopole antenna with electrically coupled metamaterial units is proposed and investigated. The proposed antenna is designed to cover WLAN/WiMAX applications. The antenna consists of a printed strip line and two double metamaterial unit cells of different size placed near the monopole antenna on opposite sides. Each unit cell exhibits a negative permeability over the resonance frequency at 2.5 GHz and 3.62 GHz, which produces magnetic couplings with the monopole antenna. The proposed antenna structure was fabricated and measured. The measured -10 dB bandwidth for the return loss is from 2.47GHz-2.51GHz, 3.59GHz-3.69GHz, and 5.3GHz - 7.2 GHz, which are suitable for (WLAN: 2.4–2.484,  5.15–5.35,  and  5.725–5.85  GHz) and  (WiMAX: 2.5–2.69, 3.4–3.8, and 5.25–5.85 GHz) band Applications. By using the switches across the gap of proposed-MTM unit cell, the effect of this unit deactivated and its resonance frequency will disappear. Hence, the proposed antenna maintains the omnidirectional radiation pattern

Design and Fabrication of a Novel Quadruple-Band Monopole Antenna Using a U-DGS and Open-Loop-Ring Resonators

In this Article, a novel quadruple-band microstrip patch antenna is proposed for the systems operating at quad-band applications. The antenna structure is composed of modified rectangular patch antenna with a U-shaped defected ground structure (DGS) unit and two parasitic elements (open-loop-ring resonators) to serve as a coupling-bridge. The proposed antenna with a total size of 31×33 mm2 is fabricated and tested. The measured result indicates that the designed antenna has impedance bandwidths for 10 dB return loss reach about 180 MHz (4.4–4.58 GHz), 200 MHz (5.4–5.6 GHz), 1100 MHz (7.2–8.3 GHz), and 700 MHz (9.6–10.3 GHz), which meet the requirements of the wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX), C and X bands applications. Good agreement is obtained between measurement and simulation results

Evaluation of Trivalent and Hexavalent Chromium Retention on Ain Oussera Soil by the Batch Method and Radiotracer Technique.

Major toxicology studies have concluded that Cr (VI) is a highly toxic carcinogen to living organisms, and cause deaths if ingested in large doses. The trivalent form plays an important role in glucose and lipid metabolism for human and animal diets. Industrial activities present in the study area investigated in this paper, such as tanning, production of paints, and cement, are the main sources of chromium in the soil and air, causing chromium pollution. The aim of this study is to investigate the behavior of Cr (III) and Cr (VI) in soil samples from the Ain Oussera area, using the batch method and radiotracer technique. This assessment of chromium adsorption in the soil allows us to examine its impact. The pH effects of initial concentration, adsorbent dose and temperature were investigated. Particle size, X-ray diffraction and neutron activation analysis methods were used to characterize the soil samples. Results of the Freundlich, and Langmuir isotherm models were compared to the obtained experimental data. The thermodynamic parameters ∆H°, ∆S° and ∆G° for the adsorption were determined by using four temperatures, 10, 30, 40 and 60°C. The adsorption process was spontaneous and favoured at a low temperature. The maximum adsorption percentage reached for Cr (III) and Cr (VI) in soil was 90 and 24, respectively, with a spontaneous reaction (∆H°< 0). These results show that hexavalent chromium seeps through soil layers, and reaches the groundwater easily

Evaluation of Trivalent and Hexavalent Chromium Retention on Ain Oussera Soil by the Batch Method and Radiotracer Technique.

Major toxicology studies have concluded that Cr (VI) is a highly toxic carcinogen to living organisms, and cause deaths if ingested in large doses. The trivalent form plays an important role in glucose and lipid metabolism for human and animal diets. Industrial activities present in the study area investigated in this paper, such as tanning, production of paints, and cement, are the main sources of chromium in the soil and air, causing chromium pollution. The aim of this study is to investigate the behavior of Cr (III) and Cr (VI) in soil samples from the Ain Oussera area, using the batch method and radiotracer technique. This assessment of chromium adsorption in the soil allows us to examine its impact. The pH effects of initial concentration, adsorbent dose and temperature were investigated. Particle size, X-ray diffraction and neutron activation analysis methods were used to characterize the soil samples. Results of the Freundlich, and Langmuir isotherm models were compared to the obtained experimental data. The thermodynamic parameters ∆H°, ∆S° and ∆G° for the adsorption were determined by using four temperatures, 10, 30, 40 and 60°C. The adsorption process was spontaneous and favoured at a low temperature. The maximum adsorption percentage reached for Cr (III) and Cr (VI) in soil was 90 and 24, respectively, with a spontaneous reaction (∆H°< 0). These results show that hexavalent chromium seeps through soil layers, and reaches the groundwater easily