bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free Convection from a Vertical Permeable Circular Cone with Pressure Work and Non-Uniform Surface Temperature
Authors: Alam Md. M. M. , Alim M. A. A. , Chowdhury Md. M. K. M. K. 
Published: October 2019

Laminar free convection from a vertical permeable circular cone maintained at non-uniform surface temperature with pressure work term is considered. Non-similarity solutions for boundary layer equations are found to exist when the surface temperature follows the power law variations with the distance measured from the leading edge. The numerical solutions of the transformed non-similar boundary layer equations are obtained by using two methodologies, namely, (i) a finite difference method and (ii) a series solution or perturbation method for small values of ξ, the dimensionless suction parameter. Solutions obtained in terms of skin-friction coefficient, local rate of heat transfer, velocity and temperature profiles for the values of Prandtl number, pressure work parameter and temperature gradient are displayed in both graphical and tabular forms. Finite difference solutions are compared with the solutions obtained by perturbation technique and found to be in excellent agreement near the leading edge.
On the Abel Equation of the Second Kind with Sinusoidal Forcing
Authors: Alobaidi G. , Mallier R. 
Published: October 2019

We consider the Abel equation of the second kind with sinusoidal forcing, which is a model equation for western boundary outflow in the Stommel model of the large scale ocean circulation. Series solutions of this equation indicate the presence of resonances at certain discrete values of a parameter which measures the nonlinearity of the flow, but numerical solutions using a standard scheme show no evidence of these resonances. We discuss and resolve this apparent contradiction.
Process Distribution in the Network Systems
Authors: Augutis J. , Ušpuras E. , Krikštolaitis R. , Matuzas V. 
Published: October 2019

Performing risk analysis of systems, evaluating reliability of technological objects, hazard of technological processes, we usually have to systems of network type and distribution of various processes in such systems. A well-known mathematical apparatus of diffusive processes example is dispersion in continuum medium (air, water, etc.). Process distribution in network systems is simpler, however, it much depends on network features. In this article theory of Markov chains is selected, distributions of different processes in transitional regimes are analysed as well as issues of their stability. Created models may be used in many different ways, for example, for the analysis or viruses in computer networks, hazard distribution in transport systems regarding transportation of hazardous materials, etc.
Some Advanced Fiber-Optical Amplitude Modulated Reflection Displacement and Refractive Index Sensors
Authors: Kleiza V. , Verkelis J. 
Published: October 2019

Some advanced fiber-optic amplitude modulated reflection displacement sensors and refractive index sensors have been developed. An improved three-fiber displacement sensor has been investigated as a refractive index sensor by computer simulations in a large interval of displacement. Some new regularities have been revealed. A reflection fiber-optic displacement sensor of novel configuration, consisting of double optical-pair fibers with a definite angle between the measuring tips of fibers in the pairs has been proposed, designed, and experimentally investigated to indicate and measure the displacement and refractive index of gas and liquid water solutions. The proposed displacement sensor and refractive index sensor configuration improves the measuring sensitivity in comparison with the known measuring methods. The refractive index sensor sensitivity Snsub = 4 × 10−7 RIU/mV was achieved. The displacement sensor sensitivity is Ssub = 1702 mV/µm in air (n = 1.00027).
A Nonlinear Dynamical Model to Study the Removal of Gaseous and Particulate Pollutants in a Rain System
Authors: Naresh R. , Sundar S. 
Published: October 2019

An ecological type nonlinear mathematical model is proposed to study the removal of gaseous pollutants and two distinct particulate matters by precipitation scavenging in the atmosphere. The atmosphere during precipitation consists of five interacting phases namely the raindrops phase, the gaseous pollutants phase, the smaller particulate matters phase, the larger particulate matters phase and the absorbed phase of gaseous pollutants. We assume that gaseous pollutants are removed from the atmosphere by the processes of impaction as well as by absorption while particulate matters are assumed to be removed by impaction process. The model is analyzed using stability theory of nonlinear differential equations. It is shown that, under appropriate conditions, the pollutants can be removed from the atmosphere and their removal rates would depend mainly upon the rates of emission of pollutants, rate of rain drops formation and the rate of raindrops falling on the ground. If the rate of precipitation is very high, all the pollutants (gaseous as well as particulate matters) would be removed completely from the atmosphere. A numerical study is also performed to study the dynamics of the model system. The results are found to be in line with the experimental observations published in the literature.
Nonlinear Spectra for Parameter Dependent Ordinary Differential Equations
Authors: Sadyrbaev F. , Gritsans A. 
Published: October 2019

Eigenvalue problems of the form x'' = −λf(x) + µg(x) (i), x(0) = 0, x(1) = 0 (ii) are considered. We are looking for (λ, µ) such that the problem (i), (ii) has a nontrivial solution. This problem generalizes the famous Fuchik problem for piece-wise linear equations. In our considerations functions f and g may be super-, sub- and quasi-linear in various combinations. The spectra obtained under the normalization condition (otherwise problems may have continuous spectra) structurally are similar to usual Fuchik spectrum for the Dirichlet problem. We provide explicit formulas for Fuchik spectra for super and super, super and sub, sub and super, sub and sub cases, where superlinear and sublinear parts of equations are of the form |x|2αx and |x|1/(2β+1) respectively (α > 0, β > 0.)
On Similarity Solutions and Interface Reactions for a Vector-Valued Stefan Problem
Authors: Vermolen F. J. J. 
Published: October 2019

In this paper first it is shown for several geometries that classical similarity solutions for particle growth exist if and only if the Stefan problem is well-posed in the sense of being mass conserving. The extension of the similarity solutions to multicomponent alloys, which makes the problem nonlinear, is illustrated by the application to a hypothetic alloy with realistic input values. The similarity solutions are based on the assumption of local equilibrium at the interface. In the second part, the assumption of local equilibrium is relaxed using a first-order interface reaction. The influence of the interface reaction on the movement of the interface and on the interface concentrations is evaluated using Finite Difference calculations. A Newton scheme is used to solve the nonlinear problem.
Numerical Modeling of Contaminant Transport with Spatially-Dependent Dispersion and Non-Linear Chemical Reaction
Authors: Chamkha A. J. J. 
Published: October 2019

A one-dimensional advective-dispersive contaminant transport model with scale-dependent dispersion coefficient in the presence of a nonlinear chemical reaction of arbitrary order is considered. Two types of variations of the dispersion coefficient with the downstream distance are considered. The first type assumes that the dispersivity increases as a polynomial function with distance while the other assumes an exponentiallyincreasing function. Since the general problem is nonlinear and possesses no analytical solutions, a numerical solution based on an efficient implicit iterative tri-diagonal finitedifference method is obtained. Comparisons with previously published analytical and numerical solutions for special cases of the main transport equation are performed and found to be in excellent agreement. A parametric study of all physical parameters is conducted and the results are presented graphically to illustrate interesting features of the solutions. It is found that the chemical reaction order and rate coefficient have significant effects on the contaminant concentration profiles. Furthermore, the scale-dependent polynomial type dispersion coefficient is predicted to obtain significant changes in the contaminant concentration at all dimensionless time stages compared with the constant dispersion case. However, relatively smaller changes in the concentration level are predicted for the exponentially-increasing dispersion coefficient.
Deterministic and Stochastic Analysis of a Ratio-Dependent Predator-Prey System with Delay
Authors: Maiti A. , Jana M. M. M. , Samanta G. P. P. 
Published: October 2019

Recently ratio-dependent predator-prey models have become the focus of considerable attention in theoretical ecology in their own right. In this paper, we have studied the deterministic and stochastic dynamical aspects of stability of a MichaelisMenten type ratio-dependent predator-prey system that includes discrete time-delay. Computer simulations are carried out to explain the analytical findings in deterministic environment. The biological implications of our analytical and numerical findings are discussed critically.
Motion of a Self-Propelling Micro-Organism in a Channel Under Peristalsis: Effects of Viscosity Variation
Authors: Radhakrishnamacharya G. , Sharma R. 
Published: October 2019

The motion of a self propelling micro-organism symmetrically located in a rectangular channel containing viscous fluid has been studied by considering the peristaltic and longitudinal waves travelling along the walls of the channel. Theexpressions for the velocity of the micro-organism and time average flux have been obtained under long wavelength approximation by taking into account the viscosity variation of the fluid across the channel. Particular cases for constant viscosity and when it is represented by a step function have been discussed. It has been observed that the velocity of the micro-organism decreases as the viscosity of the peripheral layer increases and its thickness decreases.
Stabilizing Unstable Periodic Orbits of the Multi-Scroll Chua's Attractor
Authors: Boukabou A. , Chebbah A. , Belmahboul A. 
Published: October 2019

This paper addresses the control of the n-scroll Chua’s circuit. It will be shown how chaotic systems with multiple unstable periodic orbits (UPOs) detected in the Poincar´e section can be stabilized as well as taking the system dynamics from one UPO to another.
Numerical Simulation of the Performance Characteristics of the Hybrid Closed Circuit Cooling Tower
Authors: Sarker M. M. A. M. A. , Kim E. , Moon G. C. C. , Yoon J. I. I. 
Published: October 2019

The performance characteristics of the Hybrid Closed Circuit Cooling Tower (HCCCT) have been investigated applying computational fluid dynamics (CFD). Widely reported CFD techniques are applied to simulate the air-water two phase flow inside the HCCCT. The pressure drop and the cooling capacity were investigated from several perspectives. Three different transverse pitches were tested and found that a pitch of 45 mm had lower pressure drop. The CFD simulation indicated that when air is supplied from the side wall of the HCCCT, the pressure drop can be over predicted and the cooling capacity can be under predicted mainly due to the non-uniform air flow distribution across the coil bank. The cooling capacity in wet mode have been calculated with respect to wet-bulb temperature (WBT) and cooling water to air mass flow rates for different spray water volume flow rates and the results were compared to the experimental measurement and found to conform well for the air supply from the bottom end. The differences of the cooling capacity and pressure drop in between the CFD simulation and experimental measurement in hybrid mode were less than 5 % and 7 % respectively for the uniform air flow distribution.
A Two-Dimentional Discrete Limit Theorem in the Space of Analytic Functions for Mellin Transforms of the Riemann Zeta-Function
Authors: Balinskaitė V. , Laurinčikas V. 
Published: October 2019

In the paper, a two-dimentional discrete limit theorem in the sense of weak convergence of probability measures in the space of analytic functions for Mellin transforms of the Riemann zeta-function on the critical line is obtained.
The Dynamics of Food Web Model with Defensive Switching Property
Authors: Naji R. K. K. , Kasim I. H. H. 
Published: October 2019

In this paper, a food web model consisting of two-predator one-prey with the defensive switching of predation avoidance is proposed and analyzed. It is assumed that the prey growth logistically in the absence of predators and defends itself from relatively abundant predator species by switching to another habitat with relatively rare predator species. Sufficient conditions for the stability of the non-trivial equilibrium point are obtained. The Lyapunov function is constructed to establish the global asymptotic stability of the non-trivial equilibrium point when the intensity of defensive switching equal one. Numerical simulations for different sets of parameter values and for different sets of initial conditions are carried out. It has been shown that the system has a globally asymptotically stable non-trivial point when the two predators have the same mortality rates.
Analysis of an Antiplane Contact Problem with Adhesion for Electro-Viscoelastic Materials
Authors: Sofonea M. , Chouchane L. , Selmani L. 
Published: October 2019

We consider a mathematical model which describes the antiplane shear deformation of a cylinder in frictionless contact with a rigid foundation. The adhesion of the contact surfaces, caused by the glue, is taken into account. The material is assumed to be electro-viscoelastic and the foundation is assumed to be electrically conductive. We derive a variational formulation of the model which is given by a system coupling an evolutionary variational equality for the displacement field, a time-dependent variational equation for the electric potential field and a differential equation for the bonding field. Then we prove the existence of a unique weak solution to the model. The proof is based on arguments of evolution equations with monotone operators and fixed point.
Modeling of Infantry Attacks on Real Terrain
Authors: Pincevičius A. , Baušys R. , Bekešienė S. , Kleiza V. 
Published: October 2019

The estimation of the terrain features can be completely carried out by using the Geographical Information System (GIS). GIS technologies and three-dimensional map in planning battle tactics are discussed. An infantry attack on real terrain is modeled. The stochastic model of combat is given in article.
Divisibility Properties of Recurrent Sequences
Authors: Plankis T. 
Published: October 2019

Let m, r ∈ N. We will show, that the recurrent sequences xn = xnrn−1 + 1 (mod g), xn = xn!n−1 + 1 (mod g) and xn = xrnn−1 + 1 (mod g) are periodic modulo m, where m ∈ N, and we will find some estimations of periods and pre-periodic parts. Later we will give an algorithm sophisticated enough for finding periods length in polynomial time.
“Judicial Convention” as a New Stage in the Recognition and Enforcement of Foreign Judgments
Authors: Zasemkova O. F. 
Published: October 2019

In May 2018, at the 4th and final meeting of the Special Commission of the Hague Conference on Private International Law, the draft Convention on the Recognition and Enforcement of Foreign Judgments in Civil and Commercial Matters that had been developed since 1992 was represented. It is expected that after the Diplomatic Session that will be held in the mid-2019 the draft will be finalized and the Convention will be adopted and opened for signature.In this regard, the article attempts to analyze the main provisions of the draft Convention and assess the appropriateness for the Russian Federation to access it, taking into account the fact that Russia has a limited number of international treaties permitting recognition and enforcement of foreign judgments in Russia and decisions of Russian courts abroad. Based on the results of the analysis, the author concludes that the adoption of this Convention will provide for a simple and effective basis for the recognition and enforcement of foreign judgments eligible for States with different legal, social and economic circumstances. This, in turn, will increase the practical value of court decisions ensuring the most comprehensive protection of the rights and interests of the party in whose favour the decision has been made and, as a consequence, will contribute to the attractiveness of this method of dispute resolution for parties involved in cross-border private law relations.However, the mixed attitudes of the EU and the USA to the Draft Convention raises the question of their accession to the future Convention and may significantly reduce the impact of the adoption of the document under consideration.
Comparison of standard short infusion versus prolonged infusion of Doxorubicin in relation to its cardiotoxicity in South Indian population
Authors: Jacob Roshan Koshy , Karpurmath Shashidhar V. , Nandennavar Manjunath , Angadi Veerendra 
Published: October 2019

Background: Anthracycline is one of the commonly used chemotherapeutic agents in the treatment of malignancies and their efficacy is undermined by potential life-threatening cardiotoxicity. The aim of this study is to compare the cardiotoxicity in patients receiving standard short infusion (15-30 minutes) versus prolonged infusion (6 hours) of doxorubicin in the study group.Methods: In this study 80 patients who were planned for treatment with Doxorubicin >200 mg/m2 were included in this study and they were randomly allotted to either of the treatment group. Each patient was assessed clinically (History, Pulse rate, Blood pressure) along with ECG ,ECHO prior to initiation of chemotherapy, after completion of 200 mg/m2 of Doxorubicin, 3 months and 6 months after chemotherapy.Results: There were 40 patients in each group, and they received a total of 384 cycles of Doxorubicin containing regimens according to respective protocols. The median number of cycles was four (range four to six cycles). The mean cumulative dose of doxorubicin was 271.5 mg/m2 in the group which received standard short infusion and 264 mg/m2 in the group which received the drug by prolonged infusion. However, none of the patients developed any cardiac symptoms during or after the planned chemotherapy nor was there a drop in ejection fraction on serial ECHO.Conclusions: There was no benefit of prolonged infusion of doxorubicin as compared to the standard rapid infusion in terms of doxorubicin induced cardiotoxicity. At present, standard rapid infusion is the best option.
Postoperative morbidity following Whipple’s procedure for periampullary carcinoma: a retrospective study spanning 5 years
Authors: V. Sharath Kumar , J. S. Ajith Prasad 
Published: October 2019

Background: The morbidity rates for Whipple’s procedure has remained high even as mortality rates were coming down. This study was intended to assess postoperative morbidity rates in a tertiary care centre and to compare it with other centres.Methods: Data was collected from various registers and medical records for this retrospective cohort study. All Whipple’s procedures for 5 years were included in the study. Statistical analysis was done using R statistical software and the results were tabulated.Results: There were 48 patients and half of them developed morbidity. Surgical site infection was the most common complication (18.8%) followed by pulmonary complications (12.5%) and bile leak (6.25%). Half of the patients having pulmonary complications died while nobody with surgical site infection or bile leak died.Conclusions: In this study the morbidity rates were comparable to other centres. Hypoalbuminemia is a significant predictor of morbidity. Surgical site infection was the most common morbidity. Pulmonary complications were the most common cause for death. Morbidity rate is comparable to other centres and Whipple’s procedure is a safe surgery in the tertiary centre where the study was conducted.
Measurements of the normal size of spleen and spleen to left kidney ratio among sudanese children up to five years age using ultrasonography
Authors: Suliman Awadia G. , Adam Mohammed A. , Ahmed Rihab Y. , Aburaida Raga A. , Ebrahim Ahmed A. 
Published: October 2019

Background: Knowledge of the normal range of spleen size in the population being examined is very important because there are many different pathological conditions that may alter in spleen size. Also, gender, height, weight and BMI of individual, affect the splenic length and could result in incorrect interpretation of splenic measurements, spleen to left kidney ratio is one of recent parameter mention in literature aid in diagnosis of splenomegaly in children.Methods: The study was a cross-sectional study conducted in Khartoum state at Al-Buluk and Gaafar Ibnauf Paediatric Tertiary Hospital during the period from March 2018 to August 2018. A total of 101 children (males and females) with aged ranged 1 month to 5 years included in study. A transabdominal scan was performed, and measurement of spleen and left kidney taken after an ethical verbal consent from their parents, then data analyzed by SPSS, Mean±SD. Deviation for study variables calculated then correlation between patients factors and ultrasound measurements done.Results: The study found that the mean measurements of the normal size of the spleen and spleen to left kidney ratio for children up to five years of age, Splenic length was 7.24±1.12 cm, width was 3.83±0.81 cm , thickness 2.91±0.55 cm and spleen to left kidney ratio was 1.04±0.0.70 ranged (0.86-1.23). The male have larger spleen than female with no statistically significant differences in spleen sizes between the sexes. There was a strong significant correlation between age, weight, height spleen and left kidney length (p<0.01)respectively and a moderate association with BMI (p<0.05).Conclusions: Spleen and left kidneys was growing rapidly and similarly in infant up to one year of life 1 mm\1 mm for each month and then decreasing growth rate of kidney in relate to spleen for 1 mm growth of spleen kidney grow 0.8 mm in up to five years of age. There was strong significant positive correlation between spleen and left kidney measurement with age, height, weight of individual. The spleen to left kidney ratio for children up to five years ranged (0.86-1.23) with mean 1.04, so if the ratio less or more than this ranged it should be considered in clinical context for diagnosis of splenomegaly or shrunken spleen in children up to five years of age.