Preferred Language
Articles
/
YRd5i5IBVTCNdQwCn7RU
Isolation and characterization of a tetrahydroprotoberberine alkaloid from Crassula ovata
...Show More Authors

The presence of alkaloids in Crassula ovata is a topic that is still unexplored, as there are no published studies on the matter. This study demonstrates the presence of an alkaloid compound (and its class) for the first time in Crassula ovata. The plant material was defatted with n-hexane, and a Soxhlet apparatus was used for the extraction process, while the acid-base method was used for the isolation of alkaloids from the chloroform fractions. The quaternary alkaloid was precipitated from the aqueous layer spontaneously, in high quantity. By using standard spectroscopic methods (including liquid chromatography - mass spectroscopy) we were able to clarify the structure of the precipi¬tated compound as a tetrahydroprotoberberine alkaloid based on the general fragmentation pattern of this class of alkaloids and the retro-Diels-Alder reaction; a characteristic fragmentation pathway of tetrahydroprotoberberine alka¬loids.

Scopus Crossref
View Publication
Publication Date
Mon Feb 05 2024
Journal Name
J Contemp Med Sci | Vol. 10, No. 1, January–february 2024: 77–79
The Validity of Computed Tomography Guided Lung Tru-Cut Biopsies in Achieving Accurate Tissue Results
...Show More Authors

Objective: This study aims to assess the efficacy of CT-guided true-cut biopsy as a less invasive and cost-effective diagnostic technique for peripherally placed lung lesions.

Publication Date
Tue Sep 01 2020
Journal Name
Optik
Synthesis of Ag2O films by pulsed laser deposited on porous silicon as gas sensor application
...Show More Authors

View Publication
Scopus (45)
Crossref (39)
Scopus Clarivate Crossref
Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Engineering
Optimization of Surface Roughness for Al-alloy in Electro-chemical Machining (ECM) using Taguchi Method
...Show More Authors

Electro-chemical Machining is  significant  process to remove metal with using  anodic dissolution. Electro-chemical machining use to removed metal workpiece from (7025) aluminum alloy using Potassium chloride (KCl) solution .The tool used was made from copper. In this present the optimize processes input parameter use are( current, gap and electrolyte concentration) and surface roughness (Ra) as output .The experiments on electro-chemical machining with use current (30, 50, 70)A, gap (1.00, 1.25, 1.50) mm and electrolyte concentration (100, 200, 300) (g/L).  The method (ANOVA) was used to limited the large influence factors affected on surface roughness and found the current was the large influence f

... Show More
View Publication Preview PDF
Publication Date
Mon Nov 01 2021
Journal Name
Journal Of Engineering
Stability Improvement of The Iraqi Super Grid (400kV) using High Voltage Direct Current (HVDC) Transmission
...Show More Authors

This research analyzes the level of the short circuit effect of the Iraqi super network and decides the suitable location for the High Voltage Direct Current (HVDC) connections in order to obtain the best short circuit reduction of the total currents of the buses in the network. The proposed method depends on choosing the transmission lines for Alternating current (AC) system that suffers from high Short Circuit Levels (SCLs) in order to reduce its impact on the transmission system and on the lines adjacent to it and this after replacing the alternating current (AC) line by direct current (DC) line. In this paper, Power System Simulator for Engineering (PSS/E) is used to model two types of HVDC lines in an effective regi

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Ibero- American Journal Of Exercise And Sports Psychology
THE EFFECT OF SPECIAL EXERCISES USING TWO DESIGNED DEVICES IN DEVELOPING SOME DEFENSIVE HANDBALL SKILLS
...Show More Authors

Scopus (3)
Scopus
Publication Date
Sun Mar 01 2015
Journal Name
Sust Journal Of Engineering And Computer Science (jecs)
Virtual failure influence of Roseires dam on Khartoum city using HEC-RAS Hydraulic simulation modeling
...Show More Authors

Dam break is series phenomenon that can result in fatal consequences and loss of properties. Unfortunately, the observed consequences can only be available after the dam breaks. Therefore, it is important to anticipate what will happen prior to dam break to issue suitable warning and locate the possible risk areas. This study attempts to simulate the case of dam break in Blue Nile at Roseires dam and see its consequences downstream. Roseires dam lies at a distance of 630 km south of Khartoum, Sennar dam lies at about 260 km downstream of Roseires dam. In this study hydraulic model is developed based of Hydraulic Engineering Centre (HEC), River Analysis System (RAS), and HEC- RAS. The HEC-RAS based model is calibrated and validated usi

... Show More
Publication Date
Tue Mar 12 2019
Journal Name
Lubricants
Absorption Wavebands for Discriminating Oxidation Time of Engine Oil as Detected by FT-IR Spectroscopy
...Show More Authors

Fourier Transform-Infrared (FT-IR) spectroscopy was used to analyze gasoline engine oil (SAE 5W20) samples that were exposed to seven different oxidation times (0 h, 24 h, 48 h, 72 h, 96 h, 120 h, and 144 h) to determine the best wavenumbers and wavenumber ranges for the discrimination of the oxidation times. The thermal oxidation process generated oil samples with varying total base number (TBN) levels. Each wavenumber (400–3900 cm−1) and wavenumber ranges identified from the literature and this study were statistically analyzed to determine which wavenumbers and wavenumber ranges could discriminate among all oxidation times. Linear regression was used with the best wavenumbers and wavenumber ranges to predict oxidation time.

... Show More
View Publication Preview PDF
Scopus (20)
Crossref (19)
Scopus Clarivate Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Ieee Transactions On Power Delivery
Optimal Dielectric Design of Medium Voltage Toroidal Transformer with Electrostatic Shield under Fast Front Excitation
...Show More Authors

Accurate calculation of transient overvoltages and dielectric stresses from fast-front excitations is required to obtain an optimal dielectric design of power components subjected to these conditions, which are commonly due to switching and lightning, as well as utilization of power-electronic devices. Toroidal transformers are generally used at the low voltage level. However, recent investigations and developments have explored their use at the medium voltage level. This paper analyzes the model-based improvement of the insulation design of medium voltage toroidal transformers. Lumped and distributed parameter models are used and compared to predict the transient response and dielectric stress along the transformer winding. The parameters

... Show More
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Wed Apr 25 2018
Journal Name
Earthquake And Structures
Response of circular footing on dry dense sand to impact load with different embedment depths
...Show More Authors

Scopus (7)
Scopus
Publication Date
Mon May 01 2023
Journal Name
Ain Shams Engineering Journal
Neural network modeling of rutting performance for sustainable asphalt mixtures modified by industrial waste alumina
...Show More Authors

Scopus (18)
Crossref (11)
Scopus Clarivate Crossref