In this work, the geomagnetic storms that occurred during solar cycles 23 and 24 were classified based on the value of the Disturbance Storm Time index (Dst), which was considered an indicator of the strength of geomagnetic conditions. The special criterion of Dst >-50 nT was adopted in the classification process of the geomagnetic storms based on the minimum daily value of the Dst-index. The number of geomagnetic storms that occurred during the study period was counted according to the adopted criteria, including moderate storms with (Dst >-50 nT), strong storms with (Dst >-100 nT), severe storms with (Dst >-200 nT), and great storms with (Dst >-350 nT). The statistical results showed that the total number of geomagnetic storms identified during solar cycle 23 was 571 storms, while during solar cycle 24, the number of storms decreased to 282 storms. Depending on the minimum value of Dst-index, the geomagnetic storms identified during Cycle 23 were classified into: 446 moderate, 101 strong, 19 severe, and 5 great storms. During Cycle 24, it was classified into: 247 moderate, 34 strong, and 1 severe storm. Also, the results of the study indicated that no storm of either a severe or great type was recorded during the solar cycle 24, given that this cycle witnessed low solar activity. This indicates that solar activity associated with sunspot number (SSN) corresponds to the rate of occurrence and strength of geomagnetic storms of all categories.
Applying a well-performing heat exchanger is an efficient way to fortify the relatively low thermal response of phase-change materials (PCMs), which have broad application prospects in the fields of thermal management and energy storage. In this study, an improved PCM melting and solidification in corrugated (zigzag) plate heat exchanger are numerically examined compared with smooth (flat) plate heat exchanger in both horizontal and vertical positions. The effects of the channel width (0.5 W, W, and 2 W) and the airflow temperature (318 K, 323 K, and 328 K) are exclusively studied and reported. The results reveal the much better performance of the horizontal corrugated configuration compared with the smooth channel during both melti
... Show MoreThe work involves synthesis of new quinolin-2-one Schiff bases (XIII)a,b and (XIV)a,b, pyrazoles (XI)a,b and pyrazolines (XII)a,b derivatives containing isoxazoline or pyrimidine cycle starting with chalcones. 3-Aminoacetophenone was reacted with 4-bromobenzaldehyde or 4-N,N-dimethyl aminobenzaldehyde in basic medium to give chalcones (I)a,b by Claisen-Schemidt reaction. These chalcons were reacted with hydroxylamine hydrochloride or with thiourea in basic medium to form isoxazolines (II)a,b or pyrimidine-2-thion (III)a,b ,respectively.Also the pyrimidine-2-thiones (III)a,b and isoxazolines (II)a,b reacted with 4-or 3-substituted benzaldehyde and coumarin to form Schiff bases (IV)a-f (V)a-f and quinoline derivatives (VII)a-d(VIII)a-d, re
... Show MoreA new simple sensitive and selective spectrophotometric method has been developed for the analysis of vanadium(V) in three randomly chosen samples from river water at different locations by continuous flow injection analysis. The method based on the oxidation of pyrogallol by vanadium(V) in acidic solution to form color species and the same species was determined using homemade Ayah 6SX1-T-2D solar cell analyser . Chemical and physical parameters were investigated using the high intensity of snow white light emitted diode as a source. The linear dynamic range for the instrument response versus vanadium(V) concentration was 1-200 mg.L-1 with correlation coefficient r = 0.9920. The limit of detection (S/N=3) was 70 ng/ sample from the step
... Show MoreA new simple sensitive and selective spectrophotometric method has been
developed for the analysis of vanadium(V) in three randomly chosen samples from
river water at different locations by continuous flow injection analysis. The method
based on the oxidation of pyrogallol by vanadium(V) in acidic solution to form color
species and the same species was determined using homemade Ayah 6SX1-T-2D
solar cell analyser . Chemical and physical parameters were investigated using the
high intensity of snow white light emitted diode as a source. The linear dynamic
range for the instrument response versus vanadium(V) concentration was 1-200
mg.L-1 with correlation coefficient r = 0.9920. The limit of detection (S/N=3) was 70<
A newly developed analytical method characterized by its speed and sensitivity for
the determination of cadmium (II) in aqueous solution in three randomly chosen
samples from river water at different locations via turbidimetric measurement by
Ayah 6SX1-T-2D Solar - CFI analyser. The method is based on the formation of
yellowish white precipitate for the complex Cd3[Fe(CN)6]2 by direct reaction of the
cadmium (II) with potassium hexacyano ferrate (III) in aqueous medium. Turbidity
was measured via the reflection of incident light that collides on the surfaces
precipitated particles at 0-180o. Chemical and physical parameters were investigated.
Linear dynamic of cadmium (II) is ranged from 0.05-12 mmol.L-1, with cor
Background: Dorsal plication on each side of the penis at the 2 and 10-o’clock positions had been a mainstay for correction of ventral penile curvature. However, because only the 12-o’clock position proved to be a nerve-free zone, dorsal plication at the 12-o’clock position can be advocated.
Objectives: To evaluate tunica albuginea plication with and without neurovascular bundle mobilization in patients with ventral penile curvature. Type of the study: A prospective study.
Methods: A 34 patients with a mean age of (4.8 ± 0.54) years, Who still
The skull is one of the largest bones in the body. It is classified into flat bones that maintain the important organic structures; which are the brain, eyes, and tongue. The skull is a strong support for preserving these organs but they are various according to the type of animals and the environments in which they live and the nature of their nutrition. There are many differences among living organisms in terms of the bones in the skull, their difference or disappearance and their length in the shape of the head. The samples were taken from the scientific storage in the Iraq Natural History Research Center and Museum; Cape hare Lepus capensis (Linnaeus, 1758) and Red fox Vulpes vulpes (Linnaeus, 1758) and the study was conducted o
... Show MoreThe skull is one of the largest bones in the body. It is classified into flat bones that maintain the important organic structures; which are the brain, eyes, and tongue. The skull is a strong support for preserving these organs but they are various according to the type of animals and the environments in which they live and the nature of their nutrition. There are many differences among living organisms in terms of the bones in the skull, their difference or disappearance and their length in the shape of the head. The samples were taken from the scientific storage in the Iraq Natural History Research Center and Museum; Cape hare Lepus capensis (Linnaeus, 1758) and Red fox Vulpes vulpes (Linnaeus, 1758) and the study was conducted o
... Show MoreTwo Prototypes of Transversely Excited at atmospheric pressure (TEA) Nitrogen laser systems (One Stage Blumlein Circuit and Two Stage Blumlein Circuit) were fabricated and operated. High voltage power supply with variable operating voltage (0-20 kv) and operating current (1-3A) was built and tested successfully. The gas flow rate of 15 L/ min and 10 L/ min for OSBC and TSBC was used. The performance of the fabricated systems was studied extensively reaching to the optimum operating conditions. The obtained laser output energy for the first system has linear relationship with the applied voltage. The maximum output energy was about (1.14 mJ) with (10.40) ns pulse duration and the half-wave divergence angle was about (0.1455 m rad). In the
... Show MoreAnew Solar concentrator have been designed in this paper, this concentrators Were based on the total internal reflection in a prism, the prism angles has been calculated by depending on the solar incident ray angle in baghdad for a year. The optical design consist ofa triangular presume, Where the solar cells on one side of the prism Wh?le the prism head towered the south. The results show that there is an increasing in the solar ray concentrators and the cell area is reduced.