An experimental study on an oscillating loop heat pipe consisting of three interconnected columns

This paper presents some experimental results of an extensive research on a novel oscillating heat pipe. The heat pipe is formed of three interconnected columns as different from the pulsating heat pipe designs. The dimensions of the heat pipe considered in this study are large enough to neglect the effect of capillary forces. Thus, the self-oscillation of the system is driven by the gravitational force and the phase lag between the evaporation and condensation processes. The overall heat transfer coefficient is found to be approximately constant irrespective of heat load for the experimental cases considered. The results are also compared with the previously published data by other investigators for water as the working fluid and for the same heat input range. The experimental data for the time variation of the liquid column heights and the vapor pressure are correlated algebraically, convenient for practical uses.     

Heat transfer in an oscillating vertical annular liquid column open to atmosphere

The heat transfer from a surface heated with constant heat flux to an oscillating vertical annular liquid column having an interface with the atmosphere is investigated experimentally in the present paper. The analysis is carried out for the case of different oscillation frequencies while the displacement amplitude remains constant. Based on the experimental data a correlation equation is obtained for the cycle-averaged Nusselt number as a function of kinetic Reynolds number.     

Synthesis and evaluation of some new hydrazones as corrosion inhibitors for mild steel in acidic media

Research on Chemical Intermediates - Mild steel corrosion in HCl solution is an example of corrosion in acidic mediums. The ongoing research efforts to develop novel environmentally friendly...     

Similarity of hybrid numbers

The set of hybrid numbers $𝕂$ is a noncommutative number system that unified and generalized the complex, dual, and double (hyperbolic) numbers with the relation ih =− hi =ε+ i. Two hybrid numbers p and q are said to be similar if there exist a nonlightlike hybrid number x satisfying the equality x ⁻¹ qx = p . And, it is denoted by p ∼ q . In this paper, we study the concept of similarity for hybrid numbers by solving the linear equations px = xq and qx − xp = c for $\text{◂,▸}\mathbf{p},\mathbf{q},\mathbf{c}\in 𝕂\mathbf{.}$     

A unified model for electrostatic sensors in fluid media

Nonlinear Dynamics - We present a unified model of electrostatic sensors comprising cantilever microbeam resonators in fluid media. The model couples Euler–Bernoulli beam equation to the...     

Spectroscopic and theoretical optical properties of indoleninyl-substituted dibenzotetraaza[14]annulenes

Two new macrocyclic dibenzotetraaza[14]annulene (DBTAA) compounds with indolenine ( 5 ) and pyridoindolenine ( 6 ) moieties were synthesized and characterized by spectroscopy. Both DBTAAs exhibit strong UV-Vis absorption properties in the Soret band region. The theoretical second-order nonlinear optical property, electric dipole moment (μ), dispersion-free dipole polarizability (α) and first hyper-polarizability values were calculated by density functional theory and time dependent density functional theory. The ab-initio quantum mechanical calculation by time-dependent Hartree-Fock method was utilized to investigate the dynamic dipole polarizabilities, dynamic second-order, static, and dynamic third-order (γ) hyper-polarizabilities of the DBTAAs. The configuration interaction technique of all doubly occupied molecular orbitals possesses theoretically defined single-photon absorption (OPA) specifications for the examined structures. The computed maximum OPA wavelengths on both macrocyclic compounds coincide with the preceding measurement outcomes.     

3D-pharmacophore study molecular docking and synthesis of pyrido[2,3-d]pyrimidine-4(1H) dione derivatives with in vitro potential anticancer and antioxidant activities

Some poly functionalized heterocyclic-compounds containing pyridine-moieties were readily assembled by combining differently functionalized pyridopyrimidine-6-carbonitrile derivatives 1a,b with different electrophilic and nucleophilic reagents via short synthetic routes. The structures of the prepared derivatives were ascertained from their-spectral-and elemental analyses. Some of the synthesized compounds were tested as plausible antitumor agents. Most of those tested compounds likes 7 , 9 , 10 , 11a showed cytotoxic potencies against different tumor cell lines. In addition, the assessments for their antioxidant activities have also been done and compound 9 exhibited the highest antioxidant activity while compounds 7 and 10 showed moderate activities. Finally, molecular docking studies were carried out which favorably indicated a high support for the experimental-results.