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Search Results: 1 - 10 of 6713 matches for " Mohammed Saleh Tawfik Makki "
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Synthesis of Fluorinated Heterobicyclic Nitrogen Systems Containing 1,2,4-Triazine Moiety as CDK2 Inhibition Agents  [PDF]
Mohammed Saleh Tawfik Makki, Reda Mohammdy Abdel-Rahman, Faisal Mohammed Aqlan
International Journal of Organic Chemistry (IJOC) , 2015, DOI: 10.4236/ijoc.2015.53020
Abstract: New fluorine substituted heterobicyclic nitrogen system as imidozolopyrimidines (2,3), pyrimido- 1,2,4-triazinones (4-7), 1,2,4-triazinyl-1,2,4-triazine (12-16), 1,2,4-triazinyl-1,2,4-triazinones (14-17) and substituted thiobarbituric acids (19-20), have been synthesized using the reaction of 3- amino-5,6-di (4'-fluorophenyl)-1,2,4-triazine (1) with α,β–bifunctional compounds. Structures of the title compounds were characterized by UV, IR, 1H/13C-NMR and mass spectrometric method. The studied compounds were tested for CDK2 inhibiting activity in DNA damage, as well as in vitro anti-tumor activity.
1,2,4-Triazine Chemistry Part I: Orientation of cyclization reactions of functionalized 1,2,4-triazine derivatives
Reda Mohammady Abdel-Rahman,Mohammed Saleh Tawfik Makki,Tarik El-Sayed Ali,Magdy Ahmed Ibrahim
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.3.236-245.54
Abstract: Orientation of heterocyclization reactions of functionalized 1,2,4-triazines were studied by effect of substituents in 1,2,4-triazine moieties, type of the solvent used in the reaction and the temperature effect. Also, it was found that cyclization process depended mainly on the chemoselective and regioselectivity states of the parent substrate as well as preferring cite of ring closure.
Practical Study for the Effect of Speed, Direction of Acceleration and Type of Machine on Vibrations Transferred to the Steering Wheel Horticulture Tractor Type (Goldoni)  [PDF]
Ghazwan Ahmed Dahham, Saad Tawfik Muhamed, Shamel Mohammed Saleh
Engineering (ENG) , 2019, DOI: 10.4236/eng.2019.111005
Abstract: Field an experiment was carried out in the farms of Agriculture and forestry academy at University in Nineveh. The research was conducted to investigate a practical study for the effect of four forward speeds (1.9, 2.6, 3.8 and 4.7 km/hr.) and three acceleration direction of axes lateral, longitudinal and vertical, and two types machines control (Mower and Rotovators) on the vibrations transferred to the steering wheel horticulture tractor type (Goldoni). The vibration points on the handgrip were calculated and tested. Root mean square acceleration (RMS), given in m/sec2, was calculated. Results showed increased acceleration vibration of the three directions (longitudinal, lateral and vertical) transferred to the steering wheel tractor by increased forward speed. The Mower score recorded the highest acceleration vibration for the three directions of Rotovators. The levels of vibration emitted from tractor to hand an operator during the experiment was high comparing with standard mechanical vibration. Handgrip vibration intensity in the vertical direction is bigger than the lateral and longitudinal direction. The total vibration evaluating was denoted as the square root mean of the three sum value (lateral, longitudinal and vertical) directions. The paper purpose was measuring and analyzing vibration level transferred to the steering wheel and reduces the machine vibration. This paper is helpful for design in order to increase the develop safety systems in easy and economical way.
Synthesis of New Fluorinated 1,2,4-Triazino [3,4-b][1,3,4]thiadiazolones as Antiviral Probes-Part II-Reactivities of Fluorinated 3-Aminophenyl-1,2,4-triazinothiadiazolone  [PDF]
Mohammed Saleh Tawfek Makki, Reda Mohammady Abdel Rahman, Ola Ahmad Abu Ali
International Journal of Organic Chemistry (IJOC) , 2015, DOI: 10.4236/ijoc.2015.53017
Abstract: Some new fluorinated 3-N-acyl/3-N-alkylaminophenyl-1,2,4-triazino[3,4-b][1,3,4]thiadiazolones (2-12) have been obtained from treatment of 2-(4'-fluorophenyl)-6-(2'-amino-5'-fluorophenyl)-1,2,4-triazino[3,4-b][1,3,4]thiadiazol-4-one(1) with active functional oxygen, sulfur and halogen compounds in different conditions. Former structures of the products have been characterized from elemental and spectral data (UV, IR, NMR and Mass). The new products were evaluated as potential anthelmintic drugs.
Phenolic Contents and Antioxidant Activity of Various Date Palm (Phoenix dactylifera L.) Fruits from Saudi Arabia  [PDF]
Ebtesam Abdullah Saleh, Manal Said Tawfik, Hamza Mohammed Abu-Tarboush
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.210152
Abstract: The present study aimed to estimate the individual and total phenols and antioxidant activity of the aqueous and alcoholic extracts of three premium quality date varieties (Khalas, Sukkari and Ajwa) from Saudi Arabia. In general, water extract has shown significantly higher contents of total phenols than alcoholic, especially in Ajwa (455.88 and 245.66 mg/100 g respectively). However, phenolic profile indicated that Sukkari contained the highest rutin concentration (8.10 mg/kg), whereas, catechin was approximately the same in Sukkari and Ajwa (7.50 and 7.30 mg/kg respectively). Khalas was the highest variety content of caffeic acid (7.40 mg/kg). A significant difference has indicated among extracts and varieties in suppressing lipid peroxidation. Sukkari and Ajwa have reduced the oxidation with 50% at lower concentration in water extract than alcoholic (0.63, 0.70 and 1.60, 1.43 mg/ml respectively). Furthermore, high positive linear correlation was found between total phenols in water (r = 0.96) and alcohol (r = 0.85) extracts and inhibition of lipid oxidation activity. The compounds responsible for the activity were catechin (r = 0.96), and rutin (r = 0.74) in water extract, whereas this correlation decreased in alcoholic extract (r = 0.66) for catechin and very weak (r = 0.38) for rutin. No correlation was found between caffeic acid and lipid peroxidation in both extracts. Similar significant results were obtained with DPPH test, except with Sukari, which has shown no difference between aqueous and alcoholic extracts (4.30, 4.10 mg/ml respectively).
Spectroscopy: Between Modeling, Simulation and Practical Investigation  [PDF]
Tawfik A. Saleh
Spectral Analysis Review (SAR) , 2014, DOI: 10.4236/sar.2014.21001
Abstract: Spectroscopy
Detection: From Electrochemistry to Spectroscopy with Chromatographic Techniques, Recent Trends with Nanotechnology  [PDF]
Tawfik A. Saleh
Detection (Detection) , 2014, DOI: 10.4236/detection.2014.24005
Abstract: The detection of trace levels of chemical, biological and other analytes has many important applications, including industry, forensics and environmental monitoring. Detection Journal is an international journal dedicated to the latest advancement of all areas that are related to detection. Nanotechnology based detection techniques may provide major advantages of low detection limits and rapid testing. This may allow scientists to know early about the case and provide the potential of stopping the problem at earlier stages.
Synthesis of Substituted Thioureas and Their Sulfur Heterocyclic Systems of p-Amino Salicylic Acid as Antimycobacterial Agents
Mohammed Saleh I. T. Makki,Reda M. Abdel-Rahman,Hassan M. Faidallah,Khalid Ali Khan
Journal of Chemistry , 2013, DOI: 10.1155/2013/862463
Orders of Fermi- and Plasma-Accelerations of Cosmic Rays
A. Tawfik,A. Saleh
Physics , 2010,
Abstract: The generic acceleration model for ultra high energy cosmic rays, which has been introduced in {\tt 1006.5708 [astro-ph.HE]}, suggests various types of electromagnetic interactions between cosmic charged particles and the different types of the plasma fields, which are assumed to have general configurations, spatially and temporally. The well-known Fermi acceleration mechanisms are also included in the model. Meanwhile Fermi mechanisms in non-relativistic limit adhere first- and second-order of $\beta$, the ratio of particle's velocity relative to the velocity of the stellar magnetic cloud, in the plasma field sector, $\beta$ does not play any role, i.e. zero-order. In the relativistic limit, the orders of Fermi acceleration are only possible, when applying the corresponding conditions, either elastic scatterings or shock waves. Furthermore, it is found that the coefficients of $\beta$ are functions of the initial and final velocities and the characteristic Larmor radius.
On Horn Matrix Function H2(A,A′,B,B′;C;z,w) of Two Complex Variables under Differential Operator  [PDF]
Mohamed Saleh Metwally, Mahmoud Tawfik Mohamed, Ayman Shehata
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2018, DOI: 10.4236/alamt.2018.82009
Abstract: The aim of this paper deals with the study of the Horn matrix function of two complex variables. The convergent properties, an integral representation of H2(A,A′,B,B′;C;z,w) is obtained and recurrence matrix relations are given. Some result when operating on Horn matrix function with the differential operator D and a solution of certain partial differential equations are established. The Hadamard product of two Horn’s matrix functions is studied, certain results as, the domain of regularity, contiguous functional relations and operating with the differential operator D and D2 are established.
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