Evaluate the performance of a wide band LPDA antenna and compare it with a half-wavelength antenna at frequency change

Antennas have become an indispensable basic need, especially in the area of wireless networks, and have developed in the past few decades in a very large way in terms of profit and resistance, bandwidth, bandwidth, radiation pattern, etc. in line with new and increasing requirements. In this study, we are interested in studying a broad band antenna where this antenna is very important in systems that operate on a set of frequencies rather than at a fixed frequency. The traditional antennas that are designed at a specific frequency change their response significantly if used on a wide bandwidth around the designed frequency In this study, the LPDA (Log periodic dipole Array) antenna was designed and studied in a broadband field and compared to the antenna reference of wire antennas. It is a halfwavelength antenna λ/2. The study of the effect of frequency change in the antenna radiation pattern and the radiation beam Half-power level and front-to-back ratio (F/B).

Motion and radiation of System Consisting of Two Charges

In this paper, we discussed the motion of charged particles in the external fields and the radiation of a system of two action reciprocal charges. Where we find that the motion of each charged particle, or precisely the motion of the moving charged particles in orbits has conical forms, and their foci are located in the center of inertia, and this is compatible with Kepler's problem in determining the motion of the planets. As we have shown, the results obtained are that a system consisting of two identical particles, or of different particles, with the same ratio (e / m) , can not radiate in a dipole approximation, and that the moving charge in a closed orbit continuously radiates energy. The differential cross section of particles scattering was calculated according to the Coulomb law, and the radiation value resulting from the incident of a beam of charged particles was finally calculated on a static charge (the braking radiation), where the radiation energy was found to be inversely proportional to the particle velocity as well as the cube with the radius of the radiation correction, and it is associated with the angle of scattering and the azimuth angle.

The Effect of Ultraviolet Radiation on Photosynthetic pigments in Euglena gracilis

The study was conducted during 2017 in the laboratories of the department of Botany at Tishreen University, Lattakia, Syria. The effect of ultraviolet radiation (UV-C and UVB) for different periods (0.5, 1, 3, 5, 15, 15, 30, 45, 60 minutes) on the photosynthetic pigments of Euglena gracilis (with three stages of measurements) was studied. The results showed that chlorophyll pigments were more sensitive to UV-C compared to UV-B. These reductions were correlated with the increase in the exposure time, reaching the lowest value after 60 minutes exposure (97.83, 98.73, 99.18% for chlorophyll a, chlorophyll b and carotenoids when measured after 24 hours respectively). The polyethylene films protect the chlorophyll pigments against UV radiation. The protection rate was more evident against UV-C reaching .7.7% after 24 hours in the algae exposed for 30 minutes according to the experimental conditions.

Effect of Salinity and Radiation on Regeneration of Two Potato (Solanum tuberosum L.) Genotypes Callus In vitro

Experiments were conducted to study effect of radiation and salt levels on plant regeneration from callus for two cultivars of potato i.e. Riviera and Burren, under in vitro condition. Results showed that the efficiency of radiation in induced regeneration from callus in Riviera cultivar at salt level of (10 dS m-1) and Burren cultivar at salt levels (8, 12 dS m-1). For the purpose of making sure inheritance of salinity tolerant, mutant clones (plants induced from salt tolerant calli, which planted at salt levels of 8, 10, 12 dS m-1 and plants induced from non salt tolerant calli, which planted at salt level of 6 dS m-1) and their parental cultivars (Riviera and Burren) by exposing to salt stress conditions and comparing them with control (6 dS m-1). Results revealed that the lowest percentage of reduction in plant height, number of nods per plant and tuberization were observed in salt tolerant mutants. Plant height and number of nodes/plant can be considered as selective morphological markers for in vitro salt tolerance .

Design of Photovoltaic Water Pumping System and economic feasibility study

In this paper, we present a system design of the photovoltaic pumping to provide electrical and economic comparison between two different energy supply systems: the first depends on the PV panels, and the second depending on the public grid. farm area study in the eastern countryside of Homs with the aim to supply water for irrigation and drinking.

Study of the effect of the addition of the booster on the performance of the basin solar still under the climatic conditions of the city of Homs

Solar energy being one of the most promising alternatives, this because of its availability and low cost compared to other energies. The device that uses solar energy to desalinate saline water is called the solar still. The problem at the solar still is reflected in its low efficiency, with the aim of raising it. This research presents a theoretical and experimental study for single-slope and single-basin solar stills.

Study and characterization of acoustic gain of parabolic reflector

The parabolic reflector is used in directed acoustic systems, with the aim of gettingdirectivity, as well as increasing the gain in transmission and reception. Therefore, a theoretical study was carried out to describe the factors that affect the gain of the parabolic dish in the acoustic field. The frequency-gain relationship was experimentally obtained using a parabolic dish with an elliptical aperture, in addition to the analysis of the factors that led to the deviation of the experimental relationship from the theoretical relationship.

Theoretical study for atomelectromagnetic field interaction, according to Time-dependent perturbation Theory (TDPT)

In this research, we have done Theoretical study, how to use perturbation theory in order to obtain approximate solutions of the time dependent Schrödinger equation. We also considered application of time dependent perturbation theory to case where the atomic quantum system interacts with electromagnetic radiation.

Evaluation of Radioactivity and Potential Radiation Hazard of NORM waste due to Produced Water Draining in Crude Oil Tanks Area in Banyas

Uncontrolled disposal of produced water from oil and gas industry in the environment involves the environmental hazard like contamination soil by NORM and increase the radiation exposure to terrestrial gamma radiation by workers and public. the study aims to measure radiation levels in the drainage zone and vicinity in the field of crude oil storage tanks in the site of Syrian company for oil transport in Banyas. Terrestrial gamma radiation dose was measured, the values ranged between 0.02 – 0.24 μSv.h-1. The radioactivity concentrations of NORM were determined for Ra226, Th232, K40 by gamma spectroscopy using HPGe detector in surface soil samples taken from three sites, two of them recorded the highest rate of radiation dose, while the third recorded the rate of radiation background. The Ra226, K40, Th232highestconcentrations in the soil samples were found to be 210, 213 and 55.9 Bq.kg-1, respectively. Radiation indexes were estimated. The present results were compared with results published in different countries.

Studying the Effectiveness of Polyethylene in Limiting the Effect of Ultraviolet Radiation (UV-B) on Photosynthesis Pigments and Photosynthetic Electron Transport in the Leaves of Young Sun Flower Plants (Helianthus sp.)

Young sun flower plants were exposed to ultraviolet radiation of the type UV-B (295 nm) for 3 days (2 hours per day) with or without excluding the UV-radiations using polyethylene layers (blue and transparent) (0.5 mm thick). The amount of photosynthesis pigments was measured whereby a variation in the chlorophyll contents. Chlorophyll a (chl.a) was noticed at these rates (without covering 19.59%, transparent polyethylene 3.40%, blue polyethylene 1.66%), chlorophyll b (chl.b) at rates (7.81, 25.13, 22.79%) and the total chlorophyll content (2.88, 21.76, 20.53%), while the amount of carotenoid pigments has increased in the studied samples (24.45, 19.23, 17.32%). A decrease in the rate of photosynthetic electron transport has also been noticed (88.04, 78.71, 58.81%) in the plant samples exposed to ultraviolet radiation (on the third day) without UV excluding and with transparent and blue polyethylene successively. All results were compared to the sample which was not exposed to radiation. All results indicate the negative effect of ultraviolet radiation on the chlorophyll content and the rate of photosynthetic electron transport, therefore, on photosynthesis and the productivity of sun flower plants. They also point out the importance of carotenoid pigments in protecting chlorophyll pigments from the negative effects of this radiation. Results showed the clear positive effect of polyethylene layers, specifically the blue one, in protecting plants against this radiation.