Resonance Capture for a Mercurian Orbiter in the Vicinity of Sun

Khattab, Elamira Hend,El-Salam, Fawzy Ahmed Abd,Rahoma, Walid A. The Korean Space Science Society 2021 Journal of Astronomy and Space Sciences Vol.38 No.2

In this work, the problem of resonance caused by some gravitational potentials due to Mercury and a third body, namely the Sun, together with some non-gravitational perturbations, specifically coronal mass ejections and solar wind in addition to radiation pressure, are investigated. Some simplifying assumptions without loss of accuracy are employed. The considered force model is constructed. Then the Delaunay canonical set is introduced. The Hamiltonian of the problem is obtained then it is expressed in terms of the Deluanay canonical set. The Hamiltonian is re-ordered to adopt it to the perturbation technique used to solve the problem. The Lie transform method is surveyed. The Hamiltonian is doubly averaged. The resonance capture is investigated. Finally, some numerical simulations are illustrated and are analyzed. Many resonant inclinations are revealed.

Resonance Capture for a Mercurian Orbiter in the Vicinity of Sun

Khattab, Elamira Hend,El-Salam, Fawzy Ahmed Abd,Rahoma, Walid A. The Korean Space Science Society 2021 Journal of astronomy and space sciences Vol.38 No.2

In this work, the problem of resonance caused by some gravitational potentials due to Mercury and a third body, namely the Sun, together with some non-gravitational perturbations, specifically coronal mass ejections and solar wind in addition to radiation pressure, are investigated. Some simplifying assumptions without loss of accuracy are employed. The considered force model is constructed. Then the Delaunay canonical set is introduced. The Hamiltonian of the problem is obtained then it is expressed in terms of the Deluanay canonical set. The Hamiltonian is re-ordered to adopt it to the perturbation technique used to solve the problem. The Lie transform method is surveyed. The Hamiltonian is doubly averaged. The resonance capture is investigated. Finally, some numerical simulations are illustrated and are analyzed. Many resonant inclinations are revealed.

Synthesis and Aminolysis of N,N-Diethyl Carbamic Ester of HOBt Derivatives

Khattab, Sherine Nabil,Hassan, Seham Yassin,Hamed, Ezzat Awad,Albericio, Fernando,El-Faham, Ayman Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.1

The reaction of N,N-diethyl carbamates of 1H-[1,2,3]triazolo[4,5-b]pyridin-1-ol (4-HOAt) 7, 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol (7-HOAt) 8, 1H-benzo[d][1,2,3]triazol-1-ol (HOBt) 9, 6-chloro-1H-benzo[d][1,2,3]triazol-1-ol (Cl-HOBt) 10, 6-(trifluoromethyl)-1H-benzo[d][1,2,3]triazol-1-ol ($CF_3$-HOBt) 11, and 6-nitro-1H-benzo[d][1,2,3]triazol-1-ol ($NO_2$-HOBt) 12 with morpholine and piperidine in $CH_3CN$ underwent acyl nucleophilic substitution to give the corresponding carboxamide derivatives. The reactants and products were identified by elemental analysis, IR and NMR. We measured the kinetics of these reactions spectrophotometrically in $CH_3CN$ at a range of temperatures. The rates of morpholinolysis and piperidinolysis were found to fit the Hammett equation and correlated with $\sigma$-Hammett values. The values were 1.44 - 1.21 for morpholinolysis and 1.95 - 1.72 for piperidinolysis depending on the temperature. The $Br{\phi}$nsted-type plot was linear with a $\beta_lg = -0.49 \pm 0.02$ and $-0.67 \pm 0.03$. The kinetic data and structure-reactivity relationships indicate that the reaction of 9-12 with amines proceeds by a concerted mechanism. The deviation from linearity of the correlation ${\Delta}H^#$ vs. ${\Delta}S^#$ and plot of $logk_{pip}$ vs. $logk_{morph}$ and $Br{\phi}$nsted-type correlation indicate that the reactions of amines with carbamates 7 and 8 is attributed to the electronic nature of their leaving groups.

Ensiled Banana Wastes with Molasses or Whey for Lactating Buffaloes during Early Lactation

Khattab, H.M.,Kholif, A.M.,EI-Alamy, H.A.,Salem, F.A.,EI-Shewy, A.A. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.5

Low-quality roughages [banana wastes (B), wheat straw (WS) and dried broiler litter (BL)] were ensiled using either sweet whey (W) or diluted molasses (M) as rehydration media to study their effects on milk yield, milk composition and some parameters of blood plasma. The feeding trial involved 25 lactating buffaloes in five groups (five animals each). Buffaloes as control animals received diets of concentrate feed mixture, rice straw and wastelages (70:30:00). In the other 4 treatments, the wastelages replaced 50% of rice straw in the control diets. The wastelages were BL:B:M(3:2:10) (T1), BL:WS:M (3:2:10) (T2), BL:B:W (3:2:10) (T3) and BL:WS:W (3:2:10) (T4) on a fresh matter basis, during the 1st 17 weeks of lactation period. Results indicated that feeding lactating buffaloes on wastelages resulted in slightly higher (p>0.05) milk yield, 4% fat-corrected-milk yield and feed efficiency, and slightly lowered (p>0.05) contents of milk total solids, fat and protein. Wastelages, especially BL-B-M, increased (p<0.05) milk non-protein-nitrogen and ash contents and plasma urea, GOT and GPT. The results demonstrate that banana plant wastes with some additives in silage form may be good untraditional roughage for lactating buffaloes without any adverse effect on milk production.

Design-Oriented Testing and Modeling of Reinforced Concrete Pile Caps

Khattab Saleem Abdul-Razzaq,Mustafa Ahmed Farhood 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.8

A new perspective in the design of reinforced-concrete pile caps is proposed in this paper, where the conventional approach leading to a reinforcing mesh is replaced by modelling the cap as a strut-and-tie system, in agreement with the strut-and-tie model, STM proposed by several design codes, ACI 318 included. Twelve RC pile-cap specimens were designed and manufactured. In the first group of 4 specimens the caps rest on two piles (Group A, axis-to-axis distance 300 mm), while in the second and third groups the piles are three and four, respectively (Groups B and C, axis-to-axis distance 400 mm). In each group, the first and third specimens were designed according to the traditional sectional method (reference specimens, with constant depth and lateral shoulders), while the design of the second and fourth specimens was based on the strut-and-tie method (no lateral shoulders; no corners opposite to the piles). Needless to say, the nominal design load was the same within each group. The tests clearly show that cap design based on strut-and-tie systems brings in a sizable reduction in terms of reinforcement amount and cost, accompanied by a less pronounced but still sizable extra bearing capacity.

Frozen Orbits Construction for a Lunar Solar Sail

Khattab, Elamira Hend,Radwan, Mohamed,Rahoma, Walid Ali The Korean Space Science Society 2020 Journal of Astronomy and Space Sciences Vol.37 No.1

Frozen orbit is an attractive option for orbital design owing to its characteristics (its argument of pericenter and eccentricity are kept constant on an average). Solar sails are attractive solutions for massive and expensive missions. However, the solar radiation pressure effect represents an additional force on the solar sail that may greatly affect its orbital behavior in the long run. Thus, this force must be included as a perturbation force in the dynamical model for more accuracy. This study shows the calculations of initial conditions for a lunar solar sail frozen orbit. The disturbing function of the problem was developed to include the lunar gravitational field that is characterized by uneven mass distribution, third body perturbation, and the effect of solar radiation. An averaging technique was used to reduce the dynamical problem to a long period system. Lagrange planetary equations were utilized to formulate the rate of change of the argument of pericenter and eccentricity. Using the reduced system, frozen orbits for the Moon sail orbiter were constructed. The resulting frozen orbits are shown by two 3Dsurface (semi-major, eccentricity, inclination) figures. To simplify the analysis, we showed inclination-eccentricity contours for different values of semi-major axis, argument of pericenter, and values of sail lightness number.

Bone regeneration and graft material resorption in extraction sockets grafted with bioactive silica-calcium phosphate composite (SCPC) versus non-grafted sockets: clinical, radiographic, and histological findings

Adel-Khattab, Doaa,Afifi, Nermeen S.,el Sadat, Shaimaa M. Abu,Aboul-Fotouh, Mona N.,Tarek, Karim,Horowitz, Robert A. Korean Academy of Periodontology 2020 Journal of Periodontal & Implant Science Vol.50 No.6

Purpose: The purpose of the present study was to evaluate the effect of silica-calcium phosphate composite (SCPC) granules on bone regeneration in extraction sockets. Methods: Ten patients were selected for a split-model study. In each patient, bone healing in SCPC-grafted and control ungrafted sockets was analyzed through clinical, radiographic, histomorphometric, and immunohistochemical assessments 6 months postoperatively. Results: A radiographic assessment using cone-beam computed tomography showed minimal ridge dimension changes in SCPC-grafted sockets, with 0.39 mm and 1.79 mm decreases in height and width, respectively. Core bone biopsy samples were obtained 6 months post-extraction during implant placement and analyzed. The average percent areas occupied by mature bone, woven bone, and remnant particles in the SCPC-grafted sockets were 41.3%±12%, 20.1%±9.5%, and 5.3%±4.4%, respectively. The percent areas of mature bone and woven bone formed in the control ungrafted sockets at the same time point were 31%±14% and 24.1%±9.4%, respectively. Histochemical and immunohistochemical analyses showed dense mineralized bundles of type I collagen with high osteopontin expression intensity in the grafted sockets. The newly formed bone was well vascularized, with numerous active osteoblasts, Haversian systems, and osteocytes indicating maturation. In contrast, the new bone in the control ungrafted sockets was immature, rich in type III collagen, and had a low osteocyte density. Conclusions: The resorption of SCPC granules in 6 months was coordinated with better new bone formation than was observed in untreated sockets. SCPC is a resorbable bone graft material that enhances bone formation and maturation through its stimulatory effect on bone cell function.

A Survey on MIH vs. ANDSF:Who Will Lead the Seamless Vertical Handover through Heterogeneous Networks?

Omar Khattab,Omar Alani 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.4

Effect of gamma irradiation on polymer modified white sand cement mortar composites

Magdy M. Khattab 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

This study focuses on the substitution effect of standard sand of cement mortar by different ratios ofwhite sand to prepare white sand cement mortar. The prepared samples were first cured under tap waterfor different time intervals 3, 7, 28 and 90 days. The effect of addition of 10% styrene–acrylic ester as wellas the effect of different doses of gamma rays on the physico-mechanical properties of polymer modifiedwhite sand cement mortar specimens also, discussed. Compression strength test, total porosity andwater absorption percentages were measured. The results were confirmed by scanning electron microscopy, and thermogravimetric analysis studies.

Synthesis and Aminolysis of N,N-Diethyl Carbamic Ester of HOBt Derivatives

Sherine Nabil Khattab,Seham Yassin Hassan,Ezzat Awad Hamed,Fernando Albericio,Ayman El-Faham 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.1

The reaction of N,N-diethyl carbamates of 1H-[1,2,3]triazolo[4,5-b]pyridin-1-ol (4-HOAt) 7, 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol (7-HOAt) 8, 1H-benzo[d][1,2,3]triazol-1-ol (HOBt) 9, 6-chloro-1H-benzo[d][1,2,3]triazol-1-ol (Cl-HOBt) 10, 6-(trifluoromethyl)-1H-benzo[d][1,2,3]triazol-1-ol (CF3-HOBt) 11, and 6-nitro-1H-benzo[d][1,2,3]triazol-1-ol (NO2-HOBt) 12 with morpholine and piperidine in CH3CN underwent acyl nucleophilic substitution to give the Corresponding carboxamide derivatives. The reactants and products were identified by elemental analysis, IR and NMR.We measured the kinetics of these reactions spectrophotometrically in CH3CN at a range of temperatures. The rates of morpholinolysis and piperidinolysis were found to fit the Hammett equation and correlated with σ-Hammett values.The values were 1.44 - 1.21 for morpholinolysis and 1.95 - 1.72 for piperidinolysis depending on the temperature. The Brønsted-type plot was linear with a βlg = −0.49 ± 0.02 and −0.67 ± 0.03. The kinetic data and structure-reactivity relationships indicate that the reaction of 9-12 with amines proceeds by a concerted mechanism. The deviation from linearity of the correlation ΔH# vs. ΔS# and plot of logkpip vs. logkmorph and Brønsted-type correlation indicate that the reactions of amines with carbamates 7 and 8 is attributed to the electronic nature of their leaving groups