A mechanical behavior law for the numerical simulation of the mushy zone in welding

The aim of this work is to propose a mechanical behavior law dedicated to the mushy zone located between the solid phase and the weld pool in welding. The objective is to take into account of the influence of the mushy zone in the simulation of welding in order to improve the computation of induced effects such as residual stresses

Novel synthesis, ring transformation and anticancer activity of 1,3-thiazine, pyrimidine and triazolo[1,5-a]pyrimidine derivatives

Synthesis, heterocyclization and anticancer activity of a new series of heterocyclic compounds are described. Aminothiazine 1 was obtained from the base induced condensation of thiourea, benzaldehyde and ethyl cyanoacetate. The synthesis of N-phenyl amino pyrimidine derivative 2 was obtained as a result of reaction of aniline with compound 1. Compound 2 underwent ring opening and recyclization upon reaction with HCl or H2O2/ NaOH to afford the acid derivative 3 or oxazine 4, respectively. Thiazine 1 undergoes ring transformation upon the effect of NH2OH.HCl to produce pyrimidine derivative 5. Heterocyclization of compound 1 with thiosemicarbazide followed by oxidation with I2/AcOH afforded triazolopyrimidine 6 and 7, respectively. Alkylation of compound 1 was promoted by reaction of 1 with ethyl iodide to give alkylated thiazine 8 which in turn undergo ring transformation when subjected to reaction with hydrazine hydrate to give pyrazole derivative 9. Refluxing of amino-1,3-thiazine derivative 1 with ethyl bromoacetate in the presence of Et3N produce the alkylated pyrimidine product 10. Hydrazonolysis of 1,3-thiazine 1 with hydrazine or phenyhydrazine gave pyrimidine derivatives 11a,b, respectively. Compound 11b was cyclized with carbon disulfide or formaldehyde to produce triazolopyrimidines 12 and 13, respectively. Some of the new compounds were screened for anticancer activity and significant results were found for some compounds.               KEY WORDS: 1,3-Thiazine, Pyrimidine, Triazole, Pyrazole, Anticancer activity Bull. Chem. Soc. Ethiop. 2018, 32(3), 513-522.DOI: https://dx.doi.org/10.4314/bcse.v32i3.1

Improvement of drought tolerance in five different cultivars of Vicia faba with foliar application of ascorbic acid or silicon

Aim of study: To explore the role of ascorbic acid (AsA) or silicon (Si) in improving drought tolerance in five faba bean cultivars under irrigation water deficit (IWD).Area of study: The experimental farm; 30° 36′ N, 32° 16′ E, Egypt.Material and methods: Three drip irrigation regimes (WW, well-watered, 4000 m3 water ha-1; MD, moderate drought, 3000 m3 water ha-1; and SD, severe drought, 2000 m3 water ha-1) were applied to plants, which were sprayed 25, 40, and 55 days after sowing with 1.5 mM AsA or 2.0 mM Si vs distilled water as a control.Main results: Drought negatively affected physiological attributes (photosynthetic pigments, gas exchange parameters, relative water content, membrane stability index, electrolyte leakage (EL), and lipid peroxidation), which restricted plant growth and yields, and stimulated alterations in both enzymatic and non-enzymatic antioxidant activities. However, AsA or Si application mitigated drought effects on physiological attributes, improving growth, yields and water use efficiency by raising antioxidant activities and suppressing lipid peroxidation and EL in stressful cultivars. The mitigating effects of AsA and Si were more pronounced under MD.Research highlights: ‘Nubaria-2’, ‘Giza-843’, and ‘Sakha-3’ were more tolerant than ‘Giza-716’ and ‘Sakha-4’, suggesting the use of AsA or Si to ameliorate the IWD effects on stressful cultivars. Certain physiological traits exhibited positive association with growth and seed yield, demonstrating their importance in enhancing seed yield under irrigation treatments

Monotonic Positive Solutions of Nonlocal Boundary Value Problems for a Second-Order Functional Differential Equation

We study the existence of at least one monotonic positive solution for the nonlocal boundary value problem of the second-order functional differential equation x′′(t)=f(t,x(ϕ(t))), t∈(0,1), with the nonlocal condition ∑k=1makx(τk)=x0, x′(0)+∑j=1nbjx′(ηj)=x1, where τk∈(a,d)⊂(0,1), ηj∈(c,e)⊂(0,1), and x0,x1>0. As an application the integral and the nonlocal conditions ∫adx(t)dt=x0, x′(0)+x(e)-x(c)=x1 will be considered

Multi-level Multi-objective Quadratic Fractional Programming Problem with Fuzzy Parameters: A FGP Approach

The motivation behind this paper is to present multi-level multi-objective quadratic fractional programming (ML-MOQFP) problem with fuzzy parameters in the constraints. ML-MOQFP problem is an important class of non-linear fractional programming problem. These type of problems arise in many fields such as production planning, financial and corporative planning, health care and hospital planning. Firstly, the concept of the -cut and fuzzy partial order relation are applied to transform the set of fuzzy constraints into a common crisp set. Then, the quadratic fractional objective functions in each level are transformed into non-linear objective functions based on a proposed transformation. Secondly, in the proposed model, separate non-linear membership functions for each objective function of the ML-MOQFP problem are defined. Then, the fuzzy goal programming (FGP) approach is utilized to obtain a compromise solution for the ML-MOQFP problem by minimizing the sum of the negative deviational variables. Finally, an illustrative numerical example is given to demonstrate the applicability and performance of the proposed approach

On modeling two immune effectors two strain antigen interaction

In this paper we consider the fractional order model with two immune effectors interacting with two strain antigen. The systems may explain the recurrence of some diseases e.g. tuberculosis (TB). The stability of equilibrium points are studied. Numerical solutions of this model are given. Using integer order system the system oscillates. Using fractional order system the system converges to a stable internal equilibrium. Ulam-Hyers stability of the system has been studied

Coyote multi-objective optimization algorithm for optimal location and sizing of renewable distributed generators

Research on the integration of renewable distributed generators (RDGs) in radial distribution systems (RDS) is increased to satisfy the growing load demand, reducing power losses, enhancing voltage profile, and voltage stability index (VSI) of distribution network. This paper presents the application of a new algorithm called ‘coyote optimization algorithm (COA)’ to obtain the optimal location and size of RDGs in RDS at different power factors. The objectives are minimization of power losses, enhancement of voltage stability index, and reduction total operation cost. A detailed performance analysis is implemented on IEEE 33 bus and IEEE 69 bus to demonstrate the effectiveness of the proposed algorithm. The results are found to be in a very good agreement