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A huge quantity of citrus fruit waste is produced annually worldwide as a result of citrus fruit processing plants and juice shops, which are usually disposed of in landfills. Otherwise, it is a rich source of bio-oil and refined chemicals if treated under appropriate conditions. Therefore, in this study, our focus is on the thermal decomposition of grapefruit waste in presence of a suitable catalyst. The decomposition was carried out in a salt bath and the composition of the bio-oil produced in the presence and absence of NiO was determined using gas chromatography-mass spectrometry. Thermogravimetric analysis of powdered grapefruit waste with and without NiO was also carried out from 20 to 600 °C at various heating rates. Four consecutive stages of mass loss were detected which were attributed to water evaporation, degradation of hemicellulose, cellulose, and lignin, respectively. Kinetic parameters for both catalyzed and uncatalyzed reactions were determined employing Coats-Redfern (CR) and Ozawa Flynn Wall (OFW) methods. Average values of activation energies for non-catalyzed reaction were observed as 211.92 kJmol−1 (OFW) and 241.50 kJmol−1 (CR) and for catalyzed reaction as 185.34 kJmol−1 (OFW) and 210.27 kJmol−1 (CR), respectively. It has been concluded that NiO has not only lowered the energy of activation for the decomposition process but also improved the quality of bio-oil produced. From the pyrolysis and kinetics results, it has been concluded that grapefruit waste has the prospects to become a pyrolysis feedstock for biofuel production on a commercial scale. [ABSTRACT FROM AUTHOR]

Purpose: Due to the data paucity about the functional outcomes post pyeloplasty for patients diagnosed with ureteropelvic junction obstruction (UPJO) with a preoperative age above the age of 45 years and according to the elderly definition (age ≥ 65 years), we conducted this study to clarify the different outcomes in adults presented with late hydronephrosis. Methods: We included patients who were managed by pyeloplasty with a preoperative age ≥ 45 years. We further subdivided those patients into; group (A) patient's age ≥ 65 years and group (B) patient's age ≥ 45 and < 65 years. Split renal function (SRF) difference was evaluated by the changes between the last follow-up and the baseline renogram, where 5% change was considered a significant change. Functional outcomes and factors predicting the functional recoverability post pyeloplasty were evaluated. Results: A total of 119 patients were included. The mean age was 62.3 ± 16.4 years. Group (A) and group (B) included 47 and 72 patients, respectively. After 24 months, GFR and SRF were increased at the last follow-up (P = 0.32 and 0.57, respectively). No significant functional changes were noted between both groups. Sixty two, 7 and 13 patients showed static, decreased and improved renal function. Lower preoperative SRF was the only predictor for poor functional recoverability in patients with age ≥ 45 years who were managed by pyeloplasty. Conclusion: Elderly patients should not be excluded from the corrective surgery for UPJO. Lower preoperative SRF was the only predictor for renal function deterioration post pyeloplasty. [ABSTRACT FROM AUTHOR]

Historically, Hungary has witnessed numerous waves of drought episodes, causing significant agro-economic loss. Over the recent decades, the intensity, severity and frequency of drought occurrence have dramatically shifted, with undisputable upward tendencies across many areas. Thus, the main aim of this study was to characterize drought trends, intensity and duration over Hungary during 1961–2010. To attain the study goals, the present analyses utilized climate datasets obtained from Climate of the Carpathian region project-CARPATCLIM for 1045 gridded points covering entire Hungary. Meanwhile, a well-known drought index, namely; standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) at 12-month timescales were employed for drought characterization. Furthermore, the sub-set regions of drought in Hungary were identified using S-mode of the principal component analysis. The Mann–Kendall trend test analysis showed a significant negative SPI-12 trend (P < 0.05) in 11.5% of the total points over the western part of Hungary. In comparison, 43.2% of the total numbers of the SPEI-12 time series gridded points showed a significant negative trend (P < 0.05) over the similar locale. However, both indices' trends highlighted the fact that the northeastern region is less sensitive to drought despite experiencing the highest of total drought duration. Results also suggested that the SPI-12 indicates that no significant change can be detected from 1961 to 2010 over Hungary. In contrast, the SPEI-12 exhibits that the drought waves that hit Hungary were more pronounced, with a significant positive (P < 0.05) trend of + 1.4% per decade being detected for the area affected by very extreme drought. All in all, this study is one of the primary steps toward a better understanding of drought vulnerability assessment in Hungary. [ABSTRACT FROM AUTHOR]

Purpose: To assess the ability of prosthetic rehabilitation versus surgical rehabilitation in improving the QOL for patients with maxillary defects.Material and methods: A systematic search of PubMed, Scopus data base, Cochrane database, Ovid database, and Latin America & Caribbean database for articles published before September 2017 was performed by two independent reviewers. A manual search of articles published from January 2000 to September 2017 was also conducted. Only English studies were included which evaluate the QoL in patients with head and neck cancers. Any confusion between the two independent reviewers was resolved by means of a moderated discussion between the reviewers.Results: Five studies fulfilled the inclusion criteria for this study. Many parameters were used regarding evaluation of QOL as the EORTC Head and Neck 35 assessment, UW-QOL, OHIP-14, VAS, OFS, MHI, HAD, Body Satisfaction Scale, Oral symptom check list, Swallowing, Diet consist, Pain control, Postoperative complication, and Speech. Two studies supported the surgical line of treatment for improving the QOL as compared to the prosthetic one; another two studies showed a statistically insignificant improvement in the patients’ QOL with the surgical line, while only one revealed insignificant difference in QoL with both lines of treatment.Conclusions: Surgical rehabilitation provides a better line of treatment in improving the QOL for patients with maxillary defects. On the other hand, prosthetic has proved effectiveness in the immediate post-surgical times as temporary strategy, and it has represented a good alternative when the surgical obturation is compromised. [ABSTRACT FROM AUTHOR]

The author discusses phylogenetic classification reflecting the information content of evolution and the concern over semantic content's reduction. The author also reflects on topics including the functionality of zoological nomenclature, paraphylies being banned and an ant clade Myrmicinae's phylogeny.

In this paper, new set of universal functions, Yn( χ; α); based on Goodyear’s time transformation formula will be developed analytically and computationally for the two body-initial value problem, where n is non negative integer, χ, new independent variable, a kind of generalized anomaly, and α is the reciprocal of the orbit’s semi-major axis. For the analytical developments, the proofs of the linear independence of the Y’s functions, differential and recurrence formulae satisfied by them and their relations with the elementary function are given. Full, set of the identities for the Y’s functions are listed to serve as a ready reference when need. Exact analytical expressions of the general universal Kepler’s equation for the time t∈[ tℓ, ts], together with some orbital parameters are developed as power series of χ; also some recurrence formulae are given to facilitate their computations. Finally, symbolical series solution of the general Kepler’s equation is established, and the literal analytical expressions of the coefficients of the series are listed in Horner form for efficient and stable evaluation. For the computational developments, algorithm for the evaluation of the Y’s functions is constructed. Computational initial value problem in terms of the Y’s functions is developed for which an efficient iterative method of arbitrary positive integer order of convergence ≥2 is established for the universal Kepler’s equation. The method is of dynamic natural in the sense that, on going from one iterative scheme to the subsequent one, only additional instruction is needed. The applications of the method are illustrated by numerical examples of some test orbits of different eccentricities. The numerical results are accurate and efficient. [ABSTRACT FROM AUTHOR]

In this paper the restricted three-body problem is generalized in the sense that the effects of oblateness of the three participating bodies as well as the small perturbations in the Coriolis and centrifugal forces are considered. The existence of equilibrium points, their linear stability and the periodic orbits around these points are studied under these effects. It is found that the positions of the collinear points and y-coordinate of the triangular points are not affected by the small perturbations in the Coriolis force. While x-coordinate of the triangular points is neither affected by the small perturbations in the Coriolis force nor the oblateness of the third body. Furthermore, the critical mass value and the elements of periodic orbits around the equilibrium points such as the semi-major and the semi-minor axes, the angular frequencies and corresponding periods may change by all the parameters of oblateness as well as the small perturbations in the Coriolis and centrifugal forces. This model could be applicable to send satellite or place telescope in stable regions in space. [ABSTRACT FROM AUTHOR]

This paper aims to study the rare and trace elements and the suitability of the groundwater of wadi An Numan, south of Makkah, Saudi Arabia. Detailed investigations have been carried out concerning the hydrological and hydrochemical of wadi An Numan area. The study area comprises crystalline and metamorphic rocks and Quaternary wadi fill sediments. The groundwater is mainly present in the Quaternary sedimentary fills which range in thickness from 3 to 15 m in upstream areas to more than 50 m in the downstream. Hydrologically, the annual rainfall in wadi An Numan is irregular and varies from year to year. As, Mo, Zn, P, Pb, Co, Cd, Ni, Ba, Fe, B, Si, Hg, Mn, Cr, V, Bi, Cu, U, Al, Li, Rb, Au, Cr, Sr, F, and NH are the main rare and trace elements analyzed in the groundwater samples. Distribution maps were constructed to illustrate the variations of these elements all over the studied sub-basins of wadi An Numan. In addition, the variation diagrams between these elements are also deduced and described. The chemical analyses show that the groundwater is only enriched with nitrate (NO) ions and it is suitable for agricultural and industrial uses based on the international standards and indices used for irrigation and industrial waters. [ABSTRACT FROM AUTHOR]

This paper deals with the existence of libration points and their linear stability when the more massive primary is radiating and the smaller is an oblate spheroid. Our study includes the effects of oblateness of $\bar{J}_{2i}$ ( i=1,2) with respect to the smaller primary in the restricted three-body problem. Under combining the perturbed forces that were mentioned before, the collinear points remain unstable and the triangular points are stable for 0< μ< μ, and unstable in the range $\mu_{c} \le\mu\le\frac{1}{2}$, where $\mu_{c} \in(0,\frac{1}{2})$, it is also observed that for these points the range of stability will decrease. The relations for periodic orbits around five libration points with their semimajor, semiminor axes, eccentricities, the frequencies of orbits and periods are found, furthermore for the orbits around the triangular points the orientation and the coefficients of long and short periodic terms also are found in the range 0< μ< μ. [ABSTRACT FROM AUTHOR]

In this paper, an efficient algorithm is established for computing the maximum (minimum) angular separation ρ( ρ), the corresponding apparent position angles ( $\theta|_{\rho_{\rm max}}$, $\theta|_{\rho_{\rm min}}$) and the individual masses of visual binary systems. The algorithm uses Reed's formulae (1984) for the masses, and a technique of one-dimensional unconstrained minimization, together with the solution of Kepler's equation for $(\rho_{\rm max}, \theta|_{\rho_{\rm max}})$ and $(\rho_{\rm min}, \theta|_{\rho_{\rm min}})$. Iterative schemes of quadratic coverage up to any positive integer order are developed for the solution of Kepler's equation. A sample of 110 systems is selected from the Sixth Catalog of Orbits (Hartkopf et al.). Numerical studies are included and some important results are as follows: (1) there is no dependence between ρ and the spectral type and (2) a minor modification of Giannuzzi's () formula for the upper limits of ρ functions of spectral type of the primary. [ABSTRACT FROM AUTHOR]

In this paper, four parameters analytical solution will be established for the stellar density function in globular clusters. The solution could be used for any arbitrary order of outward decrease of the cluster's density. [ABSTRACT FROM AUTHOR]

In this paper, we consider a statistical method for distance determination of stellar groups. The method depends on the assumption that the members of the group scatter around a mean absolute magnitude in Gaussian distribution. The mean apparent magnitude of the members is then expressed by frequency function, so as to correct for observational incompleteness at the faint end. The problem reduces to the solution of a highly transcendental equation for a given magnitude parameter α. For the computational developments of the problem, continued fraction by the Top-Down algorithm was developed and applied for the evaluation of the error function erf( z). The distance equation Λ( y) = 0 was solved by an iterative method of second order of convergence using homotopy continuation technique. This technique does not need any prior knowledge of the initial guess, a property which avoids the critical situations between divergent and very slow convergent solutions, that may exist in the applications of other iterative methods depending on initial guess. Finally, we apply the method for the nearby main sequence late type stars assuming that the stars of each group of the same spectral type scatter around a mean absolute magnitude in a Gaussian distribution. The accuracies of the numerical results are satisfactory, in that, the percentage errors between r and the mean values are respectively: (2.4%, 1.6%, 0.72%, 0.66%, 3.5%, 2.4%, 2%, 2.5%, 0.9%) for the stars of spectral types: (F5V, F6V, F7V, F8V, F9V, G0V, G2V, G5V, G8V). [ABSTRACT FROM AUTHOR]

In the present paper, literal analytical solutions in power series forms are developed for the radius of curvature and the expansion velocity of the zero pressure cosmological models of the universe at any time t. Also, we develop literal analytical solutions in power series forms for the inverse problem of the zero pressure cosmological model, that is to find the time $t=\tilde{t}$ (say) at which the radius of curvature of the model $R=\tilde{R}$ (say) is known. The importance of these analytical power series representations is that, they are invariant under many operations because, addition, multiplication, exponent ion, integration, different ion, etc of a power series is also a power series. A fact which provides excellent flexibility in dealing with analytical as well as computational developments of the problems related to zero pressure cosmological models.For computational developments of these solutions, an efficient method using continued fraction theory is provided. By means of the present methods we able to analyze some known zero-pressure cosmological models, of these are Einstein and De Sitter models. In addition we also analyzed some other models by which one can know if the universe keep expanding forever, or will it reach a maximal size and then turn into contraction stage. [ABSTRACT FROM AUTHOR]

In this paper, an efficient iterative method of arbitrary integer order of convergence ≥ 2 has been established for solving the hyperbolic form of Kepler's equation. The method is of a dynamic nature in the sense that, moving from one iterative scheme to the subsequent one, only additional instruction is needed. Most importantly, the method does not need any prior knowledge of the initial guess. A property which avoids the critical situations between divergent and very slow convergent solutions that may exist in other numerical methods which depend on initial guess. Computational Package for digital implementation of the method is given and is applied to many case studies. [ABSTRACT FROM AUTHOR]

Two new biphenyl esters and three biflavonoids were isolated from the aqueous methanol extract of the fruits ofSchinus terebenthefolus. The spectral data of tetrahydrorobustaflavone have been recorded and assigned for the first time. Characterization of the structures was achieved by various spectroscopic methods. [ABSTRACT FROM AUTHOR]

In this paper, a unified algorithm of Gauss method for near parabolic orbits that is valid for both elliptic and hyperbolic cases is established symbolically and numerically. [ABSTRACT FROM AUTHOR]

In this paper, universal formulations of the closest approach problem are established and solved by two methods. The first method uses the technique of one-dimensional unconstraint minimization and needs the solution of the universal Kepler's equation twice, while for the second method, a constraint minimization technique is developed and needs the solution of two nonlinear simultaneous equations. Flexible iterative schemes of quadratic up to any positive integer order are developed for the solution of the universal Kepler's equation. The two methods of the minimization process are applied for the closest approach of Hyakutake and Hale–Bopp comets, while the first method is applied to obtain the minimum angular separation of ADS 9159, ADS 2959 and ADS 11632 visual binaries as typical examples of elliptic, parabolic and hyperbolic orbits. [ABSTRACT FROM AUTHOR]

This study reanalyzes some elastomeric properties in elongation reported for poly(dimethylsiloxane) (PDMS) networks of high cross-link functionality which had been prepared by using multifunctional siloxane oligomers to end link vinyl-terminated PDMS chains. The extent of reaction of the vinyl end groups P spanned the range of 0.40 to 0.95. These networks had elongation moduli that significantly exceeded the values predicted by the Flory-Erman theory, except at very low values of P. Trends in their stress-strain isotherms, as characterized by the Mooney-Rivlin constants 2 C and the ratio 2 C/C, also appeared to be different from those predicted by theory. Neglected in such standard analyses, however, was the fact that the segments between cross-links along the junction precursor molecules can themselves act as short network chains, contributing to the modulus and giving a strongly bimodal distribution of both network chain lengths and cross-link functionalities. Of particular interest is the apparent change in functionality with extent of reaction and chain length distribution. The results thus obtained do suggest strong dependence of the observed values of the phantom modulus on the network chain-length distribution, particularly at very small values of the ratio of the length of the short chains to the long ones. Calculations based on recognition of these complications can be used to characterize more realistically the deformation of such networks. The results give much better agreement with experiment. Such behavior could be an important characteristic of elastomeric networks in general. Also, a preliminary attempt was made to bridge theory with experiment based on Kloczkowski, Mark, and Erman's recent theory of fluctuations of junctions in regular bimodal networks. The agreement between theory and experiment thus obtained is rather satisfactory and lends further support to assumptions that take into account the possibly bimodal nature of these high-functionality networks. [ABSTRACT FROM AUTHOR]

In this paper, an accurate algorithm for the method of successive approximations for near-parabolic orbits is established symbolically. Numerical applications are given for motion predictions at fifteen epochs between the years 66 to 1835 for Halley's comet, and at fifteen epochs between the years 1417 to 1782 for Encke's comet. Comparisons with the standard Gauss method [4] show that the present algorithm is very accurate and efficient for motion predications of near-parabolic orbits. [ABSTRACT FROM AUTHOR]

In this paper, an accurate algorithm for the method of successive approximations for near-parabolic orbits is established symbolically. Numerical applications are given for motion predictions at fifteen epochs between the years 66 to 1835 for Halley's comet, and at fifteen epochs between the years 1417 to 1782 for Encke's comet. Comparisons with the standard Gauss method [4] show that the present algorithm is very accurate and efficient for motion predications of near-parabolic orbits. [ABSTRACT FROM AUTHOR]

An expression is derived for the spin-orbit potential between two heavy ions on the basis of the single-folding method. As an example theF−Si potential is calculated, and satisfactory agreement with the empirical results is obtained. [ABSTRACT FROM AUTHOR]

In this paper, economical and stable recurrence formulae for the Earth's zonal potential and its gradient for Burdet's regularized theory will be established for any number N of the zonal harmonic coefficients. A general recursive computational algorithm based on these formulae is also established for the initial value problem of Burdet oscillator for the prediction of artificial satellites in the Earth's gravitational field with axial symmetry. Applications of the algorithm for the problem of the final state prediction are illustrated by numerical examples of three test orbits each for two geopotential models corresponding to N = 2 and N = 36. A final state of any desired accuracy is obtained for each case study, a result which shows the flexibility of the algorithm. [ABSTRACT FROM AUTHOR]

Transfer reactions leading to unbound states are studied by means of the diffraction model. The unbound state is described by a resonance scattering wave function. The radial integrals are evaluated using some reasonable approximations. Comparison with the experimental results is very satisfactory. [ABSTRACT FROM AUTHOR]

In this paper, the initial value problem of space dynamics in universal Stumpff anomaly ψ is set up and developed in analytical and computational approach.For the analytical expansions, the linear independence of the functions Uj(ψ;ς); j=0,1,2,3 are proved. The differential and recurrence equations satisfied by them and their relations with the elementary functions are given. The universal Kepler equation and its validations for different conic orbits are established together with the Lagrangian coefficients. Efficient representations of these functions are developed in terms of the continued fractions.For the computational developments we consider the following items: Top-down algorithm for continued fraction evaluation.One-point iteration formulae.Determination of the coefficients of Kepler’s equation.Derivatives of Kepler’s equation of any integer order.Determination of the initial guess for the solution of the universal Kepler equation.Finally we give summary on the computational design for the initial value problem of space dynamics in universal Stumpff anomaly. This design based on the solution of the universal Kepler’s equation by an iterative schemes of quadratic up to any desired order ℓ. [ABSTRACT FROM AUTHOR]

In addition to 5,7,3′-trihydroxy-6,4′-dimethoxyflavone, 5,7,3′-trihydroxy-6,8,4′-trimethoxyflavone, isoscutellarein, luteolin, and luteolin-7- O-glucoside, the methanol extract of the aerial parts of Stachys aegyptiaca yielded a new flavone identified as luteolin 3′,4′-dimethylether-7- O- β-D-glucoside on the basis of chemical and spectroscopic methods. [ABSTRACT FROM AUTHOR]

In addition to diadzen, genisten, luteolin, apigenin, and apigenin-7-O-neohesperidoside, the methanol extract of the aerial parts of Astragalus peregrinus yielded a new isoflavone identified as 7-hydroxy-3′,5′-dimethoxyisoflavone. [ABSTRACT FROM AUTHOR]