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The Gravitomagnetic and Field Magnetic Centrifugal Force Using Force and Four-Dimensional Potential Concepts

Natural Science 2022年第3期14卷 125-132页

作者： Mohamed Yahia Shirgawi Zoalnoon Ahmed Abeid allah Saad mubarak dirar abd-alla yagoub Department of Physics Faculty of Art and Science at Al Muznab Al Qassim University Buraydah Saudi Arabia Department of Physics Faculty of Arts and Sciences at Dhahran Aljanoub King Khalid University Abha Saudi Arabia Department of Physics Faculty of Science Sudan University of Science and Technology Khartoum Sudan

Unification of fundamental forces is the dream of physics. Nevertheless, unfortunately gravitational force operators to be isolated in its geometrical content from other forces. This encourages some researchers to propose the so-called gravimagnetic field to unify gravity with other forces and to explain some cosmological problems at the early universe. This motivates to construct a new model to confirm the existence of gravitomagnetic and a corresponding magnetic field associated with any field. Using the formal Newton definition of force and considering the magnetic force to be related to the time varying mass, the magnetic force is shown to be equal to the centrifugal force. This equality is typical when treating a particle as string. Using also the definition of force in terms of potential and electric force only, energy is shown to be conserved. The Newton force can be defined also in terms of four-dimensional potential with the time varying part related to the magnetic potential. When the particle is treated as a string, energy conservation holds, while for ordinary particle, the Lagrangian is conserved. The energy conservation holds for special relativity also for energy per unit mass. The definition of acceleration for forces that obeys inverse square law shows also the magnetic force is equal to the centrifugal force.

关键词： Gravitomagnetic Force Magnetic Force Newton Force Special Relativity Centrifugal Force Energy Lagrangian

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Equivalence of String Classical and Quantum Energy beside Equivalence of Wave Packet and Relativistic Velocity in Eucleadian and Curved Space

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Natural Science 2020年第7期12卷 520-525页

作者： Mashair Ahmed Mohammed Yousif Abeer Mohammed Khairy Ahmed Zainab Mustapha Kurawa Omer A. M. Elnor mubarak dirar abd-alla yagoub Ibrahim Mohammed Elfaki El-Tahir Mohammed Idriss Ahmed Zoalnoon Ahmed Abeid allah Saad Department of Physics Faculty of Science and Education at Alkurma Taif University Alkhurma Kingdom of Saudi Arabia Department of Physics Faculty of Art and Science at Al Muznab Al Qassim University Al Muznab Kingdom of Saudi Arabia Department of Physics School of Science Education Saadatu Rimi College of Education Kumbotso Nigeria Department of Physics Faculty of Science University of Bakhtalruda Ed Dueim Sudan Department of Physics Faculty of Science Sudan University of Science and Technology Khartoum Sudan Department of Natural and Applied Sciences College of Science and Humanities at Afif Sharga University Afif Kingdom of Saudi Arabia College of Arts and Sciences King Khalid University Dhahran Saudi Arabia

Plank quantum and classical string energy relations seem to be uncorrelated. This work correlated them. The relativistic energy-momentum relation has been used together with plank and de Brogglie hypothesis to prove that the wave group velocity is equal to the particle velocity in both ordinary and curved space. The plank energy relation is shown also to be related to the classical energy relation of an oscillating string. Starting from plank energy relation for n photons and performing integration, the expression of classical string energy was obtained. This means that one can treat electromagnetic waves as a collection of continuous photons having frequencies ranging from zero to w. Conversely, starting from classical string energy relation by differentiating it with respect to angular frequency, the plank quantum energy for n photons has been found. This means that the quanta results from separation of electromagnetic waves to single isolated waves. Each wave consists of n photons or quanta.

关键词： Plank Energy Classical Energy String Quanta Photons Electromagnetic Waves Curved Space Group Velocity Wave Packet

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Exploring Trees Diversity and Ecological Value of Mountain Forests in the Blue Nile Region of Sudan

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Open Journal of Ecology 2024年第3期14卷 245-256页

作者： Dafa-alla M. Dafa-alla Haytham H. Gibreel Ahmed A. H. Siddig Yousif E. yagoub Hashim A. abdelkarim Khatir H.T. Saeed Ahmed I. Abuelbashar Faculty of Forestry-Shambat University of Khartoum Khartoum Sudan Harvard Forest Harvard University Petersham MA USA Faculty of Forest Science and Wood Technology University of Gezira Wad-Medani Sudan Department of Forestry and Range Sciences Faculty of Natural Resources and Environmental Studies Alsalam University Alfula Sudan Forest Research and Gum Arabic Centre Agricultural Research Corporation Khartoum-Soba Sudan

We carried out this research at Abu-Gaddaf Natural Forest Reserve (ANFR) which is located east of Blue Nile River, in Blue Nile State, Sudan. It aims at exploring tree composition assessing their diversity indices, and ecological importance values. For survey of types and estimation of density of tree species in the forest, we randomly distributed 97 circular sample plots (0.1 hectare (ha)). In each sample plot we identified all trees to the species level, recorded their frequencies and computed species diversity and importance value indices (IVI). A total of 13 tree species, which belong to 12 genera and nine families, were identified in the tree layer of the forest. Mean tree density in ANFR was 116 trees/ha, composed mainly of Boswellia papyrifera (Del.) Hochst. (48), followed by Combretum hartmannianu (19) and Lannea fruticosa (18). Fabaceae was the most common family followed by Combretaceae and Malvaceae. B. papyrifera Delile Hochst was the most abundant while Acacia seyal was the least abundant species. Species richness (R = 1.71), evenness (E = 0.69), dominance (0.24) indices and Simpson’s Index of Diversity (D' = 0.76) suggest a moderate diversity, moderate numbers of individuals in each species and a moderate community stability. The research provides empirical results on diversity and ecological importance value of species, signifies the urging need to safeguard threatened species and to prioritize them for conservation, as well as the need to promote management of abundant species to provide multiple forest ecosystem services.

关键词： Tree Species Diversity Dry-Land Forest Sudan

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The Impact of Nitrogen-Fixing Bacteria, Iron, and Zinc Foliar Application on Dry Land Yellow Mustard (Brassica juncea) Grain and Oil Production

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Agricultural Sciences 2024年第7期15卷 719-728页

作者： Saeid Zehtab Salmasi Haleh Nasiri Rezvan Heshmati Mohammad Reza Sarikhani yagoub Raei Sustainable Agriculture Science Center Department of Plant and Environmental Sciences New Mexico State University Alcalde New Mexico USA Department of Plant Ecophysiology University of Tabriz Tabriz Iran Department of Soil Science University of Tabriz Tabriz Iran

The study, conducted at the Research Farm of the College of Agriculture, University of Tabriz in 2021, focused on the effects of various nitrogen-fixing bacterial isolates, biofertilizers containing nitrogen and phosphorus, as well as iron and zinc foliar applications on mustard growth under rainfed conditions. The results indicated that biofertilizers, whether used alone or in combination with chemical fertilizers, produced comparable grain and oil outputs compared to chemical fertilizers alone. Additionally, the application of iron and zinc through foliar spraying significantly enhanced both grain and oil production. These findings suggest that integrating nitrogen-fixing bacteria and biofertilizers could reduce reliance on chemical nitrogenous fertilizers, leading to decreased production expenses, improved product quality, and minimized environmental impact. This study highlights the potential for sustainable agricultural practices in dry land farming as a viable alternative to traditional chemical-intensive methods. Substituting chemical nitrogenous fertilizers with nitrogen-fixing bacteria or biofertilizers could result in cost savings in mustard grain and oil production while promoting environmental sustainability.

关键词： Nitrogen Fixing Bacteria Yellow Mustard Dry Land Farming Iron Zinc Foliar Application

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POLYMER-CLAY NANOCOMPOSITES:CHEMICAL GRAFTING OF POLYSTYRENE ONTO CLOISITE 20A

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Chinese Journal of Polymer Science 2012年第6期30卷 815-823页

作者： yagoub Mansoori Khadijeh Roojaei Mohammad RezaZamanloo Gholamhassan Imanzadeh Department of Applied Chemistry Faculty of ScienceUniversity of Mohaghegh ArdabiliArdabil 56199-11367Iran

An account of the experiments on preparing polystyrene （PS） nanocomposites through grafting the polymer onto organophilic montmorillonite is reported. Cloisite 20A was reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction may liberate HC1, it was performed in the presence of sodium hydrogencarbonate to prevent the exchange of quaternary alkylammonium cations withH＋ ions. Only the silanol groups on the edge of the clay react with vinyltrichlorosilane. The radical polymerization of the product with styrene as a vinyl monomer leads to chemical grafting of PS onto the montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed by infrared spectroscopy. The prepared nanocomposite materials and the grafted nano-particles were studied by XRD. Exfoliated nanocomposites may be obtained for 0.5 wt%-1wt% clay content. The nanocomposites were studied by thermogravimertic analysis （TGA） dynamic thermal analysis （DTA） and dynamic mechanical analysis （DMTA）.

关键词： Grafting Polystyrene Nanocomposites Cloisite 20A Organophilic clay.

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THERMALLY STABLE POLYMERS BASED ON 1,3,4-OXADIAZOLE RINGS

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Chinese Journal of Polymer Science 2010年第1期28卷 21-28页

作者： yagoub Mansoori Raana Sarvari Mohammad Reza Zamanloo Gholam Hassan Imanzadeh Department of Applied Chemistry College of ScienceUniversity of Mohaghegh Ardabili

In the present work, new thermally stable polymers containing 1,3,4-oxadiazole units have been synthesized through Huisgen reaction of the aromatic bis-tetrazole compounds with the aromatic/aliphatic bis-acid chlorides in pyridine as solvent. The obtained polymers are insoluble or slightly soluble in polar aprotic solvents such as DMSO and DMF. Thermal analyses of the polymers using DSC and TGA techniques showed that the polymers had improved thermal stabilities. The model reaction was also investigated and the resulting bis-1,3,4-oxadiazole compounds were characterized by conventional spectroscopic methods.

关键词： 1,3,4-Oxadiazole Thermally stable polymers Bis-tetrazole Huisgen reaction.

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Loading and releasing behavior of carboxymethyl cellulose and chitosan complex beads

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Progress in Natural Science:Materials International 2022年第6期32卷 715-723页

作者： Ali A.Altam Liping Zhu Dafaalla Babiker Hajo yagoub Shuguang Yang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Center for Advanced Low-dimension Materials Donghua University

The complex beads of carboxymethyl cellulose（CMC） and chitosan（CHI） that are fabricated by interfacial complexation have a core-shell structure composed of a thin skin layer and a 3D entangled internal structure,which endows the beads with adsorption possibilities toward anionic and cationic molecules via electrostatic ***,the loading and releasing behavior of such a system is essential and fundamental for their application yet has not been studied *** this work,the influences of beads physical state,adsorbent dosage,agitation speed,solution pH and temperature on the loading behavior were *** CMC@CHI beads demonstrated different loading efficiency to three typical dyes of methylene blue（MB）,acid blue-113（AB）,and methyl orange（MO） with different charge *** adsorption rate followed an order of MB>AB>MO,giving 97.4%,73.3% and 20.2%,*** releasing of three dyes from CMC@CHI beads also exhibited different rates,and MB release was found to be prolonged compared to AB and *** loading mechanism of dyes was further investigated via X-ray photoelectron *** CMC@CHI beads may have possible applications in mixed dye removal as well as encapsulating systems of drugs or sensitive chemicals with different charges.

关键词： Polysaccharide Encapsulation Loading mechanism Dye removal Interfacial complexation

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Transesterification Reaction of Dimethyl Terephthalate by 2-Ethylhexanol in the Presence of Heterogeneous Catalysts under Solvent-free Condition

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Chinese Journal of Chemistry 2007年第2期25卷 246-249页

作者： FIRDOVSI, Seyidov Tataroglu yagoub, Mansoori PARVIN, Alizadeh Eslami Department of Chemistry Azad Islamic University of Tabriz Darvaze Tehran Tabriz Iran Department of Chemistry College of Science Mohaghegh Ardebili University Ardebil Iran

In this study, the synthesis of bis-（2-ethylhexyl） terephthalate, via the transesterification reaction of dimethyl terephthalate （DMT） by 2-ethylhexanol in the presence of different heterogeneous catalysts, such as Pb（OAc）2·3H2O, Cd（OAc）2·2H2O, Zn（OAc）2·2H2O, Hg（OAc）2·Ca（OAc）2·H2O, Cu（OAc）2·H2O, NaOAc, CaCO3, CaO, ZnSO4·7H2O, and sulfated zirconia, has been investigated. The reactivity of the catalysts in the reaction progress has been studied and compared. It was found that, hydrated cadmium acetate and sulfated zirconia were reactive catalysts to this reaction. The extent of transesterification of methyl ester groups reached up to 93% and 85.6% using these catalysts, respectively.

关键词： transesterification dioctyl terephthalate heterogeneous catalyst plasticizer solvent-free reaction

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Exploring tree diversity and stand structure of savanna woodlands in southeastern Sudan

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Journal of Arid Land 2020年第4期12卷 609-617页

作者： Ahmed M M HASOBA Ahmed A H SIDDIG Yousif E yagoub Faculty of Forest Sciences and Technology University of GeziraMadani 22212Sudan Faculty of Forestry University of KhartoumKhartoum North 13314Sudan Department of Environmental Conservation University of Massachusetts AmherstAmherst 01003USA

Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots(1000 m^2 for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height(DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species(Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm^2 and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.

关键词： species diversity stand structure savanna woodland ecosystem forest monitoring forest management ecosystem services Nuara Reserved Forest

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Effect of Diode Laser 810nm in Hardness of Dental Ceramic

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Optics and Photonics Journal 2014年第5期4卷 104-112页

作者： mubarak M. Ahmed abdelaziz Hagar abdelrahman Elhadi Mohieldin Samia Omer yagoub Laser system Department Laser Institute Sudan University of Science and Technology Khartoum Sudan Restorative Dentistry Faculty of Dentistry University of Medical Science and Technology Khartoum Sudan

This research study the effect of diode laser (810 nm), with various power (30, 200, 500) mW in hardness of the material used in the combinations of teeth (ceramics). Hardness was measured for dental ceramic samples divided into four groups, each group containing ten test sample, before and after it irradiated with the diode laser with wavelength 810 nm and different power (30, 200, 500) mW, with irradiation power of 200 mW for duration two minutes and ten minutes to the third and fourth groups, and irradiation power of 30 and 500 mW for duration one minute for the last two groups. The results showed that the increase in the irradiated time of the samples from two minutes to ten minutes, as well as increased power from 30 to 500 mW does not have a significant effect in increasing the hardness of the ceramic material. This study found that the hardness ratio of the samples was increased up to (18.28%), by irradiation of invisible diode laser 810 nm, 30 mW.

关键词： Dental Ceramic Invisible Laser Irradiation Hardness

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