637 research outputs found

    Hydrological modelling of ungauged arid volcanic environments at upper Bathan catchment, Madinah, Saudi Arabia

    Get PDF
    Hydrological modelling of ungauged catchments is still a challenging task especially in arid regions with a unique land cover features such as highly fracture volcanic basalt rocks. In this study, upper Bathan catchment (103 km2) in Madinah, western of Saudi Arabia is selected. The aim of this paper is to simulate the hydrological responses of volcanic catchment to daily design storm events. The weighted areal average of two daily design rainfall depth scenarios are computed, which are 50 years and 100 years return period and correspondent predicted rainfall are 80.6 mm and 94.1 mm, respectively. SCS Type II temporal synthetic distribution of daily rainfall is selected to disaggregate the daily rainfall into smaller time interval. Excess rainfall is computed using Soil Conservation Services Curve Number (SCS-CN) method based on Land Cover and Land Use (LCLU) and hydrological soil groups (HSG) maps, while direct runoff hydrograph is developed using Soil Conservation Services dimensionless unit hydrograph (SCS-UH) method using lag time equation. HEC-HMS software is used, and it showed that the runoff volumes of the two rainfall scenarios are 50% and 54% of the total rainfall depth, and the peak discharges are 123 m3/sec and 158 m3/sec. This study provided an indication of the hydrograph characteristics of basaltic catchments and the result of this paper can be used for further flood studies in arid ungauged volcanic catchments

    Investigation of graphene channel interaction with yeast cell for cell counting application

    Get PDF
    Graphene superior and unique properties make it a suitable material for biosensor. In this work, graphene interaction with yeast cell is investigated for development of graphenebased cell counter. The fabricated graphene channel was characterized by means of two-terminal and solution-gated three-terminal measurement setup. The correlation between graphene channel resistance and cell concentration was confirmed. The yeast cell was found to give n-type doping which modulate the conductivity of graphene channel

    Characterization of adsorbent from pineapple peel waste for adsorption of Fe(III)

    Get PDF
    The present study explores the capability of pineapple peel, an agricultural effluent, to be converted into adsorbent targeted for the removal of Fe(III). The adsorbent was prepared from pineapple peel waste using a chemical activation method impregnated with zinc chloride (ZnCl2), and the morphological and functional characterization of the adsorbent was performed using BET, FTIR, and SEM. SEM images show rough surfaces of raw pineapple peel and has creases. However, after the chemical treatment, the surface of the adsorbent appears to be highly cave-like and porous due to the removal of substances such as pigments, gum, and other acid-soluble oligosaccharides. Raw pineapple peel contained more functional groups, including O–H stretching vibration at 3300 cm−1 and C–H vibration at 2917 cm−1, compared to the adsorbent with the disappearance of some distinctive peaks. The ability of the adsorbent to remove Fe(III) ions at different contact times and adsorbent dosages was studied. As the contact time and adsorbent dosage increased, the adsorption capacity also increased. The results provide the evidence to support the potential use of pineapple peel waste as an effective adsorbent for the treatment of wastewater in removing of Fe(III) ion

    An active downlink photonic antenna

    Get PDF
    This paper presents an active photonic antenna concept whereby an interface circuit is introduced in order to integrate the antenna with the photodiode. The operating frequencies ranges are 1.8 to 3.5 GHz which support the GSM 1800, WLAN and WiMAX applications. The simulated and measured results of interface circuit and antenna are presented. Thus, the photonic antenna is developed by integrating photodiode, interface circuit, RF amplifier and printed antenna and fabricated on FR4 board. The experiment was setup and spectrums at desired frequencies were measured. Measurement results show that an active downlink photonic antenna (ADPha) is successfully developed

    A novel green antenna phase-shift system with data acquisition boards

    Get PDF
    A novel green phase shifter system is proposed in this research. The system is developed by a combination of reconfigurable beam steering antennas and data acquisition (DAQ) boards. A combination of two reconfigurable beam steering antennas, located side-by-side, forms a spatial configuration structure with a fabricated ‘green’ element plank of rice husk placed in between. The concept of a spatial configuration technique has been ‘mutated’ by shifting the structure of spiral feed line and aperture slots of first beam steering antenna by as much as 45 ◦ . The PIN diode switches connected to the DAQ boards enable the intelligent capability of the spatial antennas. The activation of certain degree radiation patterns of either the first beam steering antenna or the second beam steering antenna depends on the memory of the DAQ boards — Beam Manager. When an intruder comes from the cardinal angles of 0◦/ 360◦, 90◦, 180◦, or 270◦, its range and angles’ location will be automatically detected by the first antenna through the output ports of the 1st DAQ: P1.0, P1.1, P1.2, and P1.3. The second antenna is then activated by the output ports of the 2nd DAQ: P2.0 up to P2.3, to adaptively maneuver the beam towards four different ordinal directions of 45◦, 135◦, 225◦, and 315◦

    Effect of vitamin B17 on experimentally induced colon cancer in adult male albino rat

    Get PDF
    Background: Colon cancer is considered to be the third most common cancer worldwide. At diagnosis of colon cancer, 3.7–11% developed bone metastasis. Diet based strategies are important for prevention and treatment of colon cancer. This study investigated the effect of vitamin B17 on a DMH induced rat model of colon cancer. Materials and methods: Eighty young adult male albino rats were divided into five groups: group I (control group), group II (vitamin B17), group III (colon cancer), group IV (protected) and group V (treated). Distal colon sections were prepared for light and scanning electron microscopic examination. Lumbar vertebrae specimens were prepared for light microscopic study. Morphometric and statistical analysis were done. Results: In comparison with the control, both colon cancer and treated groups showed invasion of the colonic tissue by pleomorphic branching colonic glands of variable shapes and sizes lined with dysplastic elongated hyperchromatic nuclei with frequent mitotic figures or stratified multi-layered crowded nuclei with an extremely significant (p < 0.0001) reduction of goblet cell number when compared to the control together with major pathological bone changes were observed in colon cancer and the treated groups. Conclusions: While the protected group showed impressive improvement of all previously mentioned diameters

    Micropropagation and production of eurycomanone, 9- methoxycanthin-6-one and canthin-6-one in roots of Eurycoma longifolia plantlets

    Get PDF
    Eurycoma longifolia or Tongkat Ali is a well known medicinal plant in Malaysia. The plants are used as main portion in herbal preparation, and have been extensively harvested. Generally, most of the raw materials required by the industries are heavily collected from the natural forests, thereby resulting in the uncontrolled exploitation of the plant in the wild. Hence, there is a need to ensure adequate supply of quality E. longifolia for the use of the related industries and for conservation purposes. Micropropagation has proved to be an alternative for the multiplication of medicinal and aromatic plants and it can allow the future commercial use of E. longifolia in the herbal industries. In this study, E. longifolia plantlets were successfully mass-produced using axillary shoot multiplication techniques, and the production of eurycomanone, 9-methoxycanthin-6-one and canthin-6-one compounds of E. longifolia were detected in roots of tissue culture plantlets.Key words: E. longifolia, Tongkat Ali, micropropagation, eurycomanone, 9-methoxycanthin-6-one, canthin-6- one

    Suppression of Staphylococcus aureus biofilm formation and virulence by a benzimidazole derivative, UM-C162

    Get PDF
    Staphylococcus aureus is a major cause of nosocomial infections and secretes a diverse spectrum of virulence determinants as well as forms biofilm. The emergence of antibiotic-resistant S. aureus highlights the need for alternative forms of therapeutics other than conventional antibiotics. One route to meet this need is screening small molecule derivatives for potential anti-infective activity. Using a previously optimized C. elegans - S. aureus small molecule screen, we identified a benzimidazole derivative, UM-C162, which rescued nematodes from a S. aureus infection. UM-C162 prevented the formation of biofilm in a dose-dependent manner without interfering with bacterial viability. To examine the effect of UM-C162 on the expression of S. aureus virulence genes, a genome-wide transcriptome analysis was performed on UM-C162-treated pathogen. Our data indicated that the genes associated with biofilm formation, particularly those involved in bacterial attachment, were suppressed in UM-C162-treated bacteria. Additionally, a set of genes encoding vital S. aureus virulence factors were also down-regulated in the presence of UM-C162. Further biochemical analysis validated that UM-C162-mediated disruption of S. aureus hemolysins, proteases and clumping factors production. Collectively, our findings propose that UM-C162 is a promising compound that can be further developed as an anti-virulence agent to control S. aureus infections.Cin Kong, Chin-Fei Chee, Katharina Richter, Nicky Thomas, Noorsaadah Abd. Rahman and Sheila Natha
    corecore