How can aviation law and policy facilitate open access to the new airport of Istanbul

Dr. Mendes de Leon as legal professor and expert in aviation touched on several legal aspects that Turkey’s airports, airlines and authorities could think when preparing for the opening of the new airport.Dr. Mendes de Leon, Hukuk profesörü ve Havacılık alanında bir uzman olarak, Türkiye’nin havaalanlarının, havayollarının ve otoriterinin, yeni bir havaalanı açmaya hazırlandıklarında düşünebilecekleri bir kaç yasal açıya değindi

Effect of trapezoidal discrete heater sizes on evolution of laminar thermal plumes in enclosures

In this study, numerical simulation of unsteady laminar natural convection in a cubical cavity having discrete heat source of a trapezoidal shape has been carried out. Governing equations describing fluid flow and heat and mass transfer within the considered area have been represented using the dimensionless vector potential functions, vorticity vector and temperature. Distributions of velocity and temperature fields inside the domain of interest have been obtained. All calculations have been conducted in a wide range of Rayleigh number and heater size

Modeling molecular crystals formed by spin-active metal complexes by atom-atom potentials

We apply the atom-atom potentials to molecular crystals of iron (II) complexes with bulky organic ligands. The crystals under study are formed by low-spin or high-spin molecules of Fe(phen)$_{2}$(NCS)$_{2}$ (phen = 1,10-phenanthroline), Fe(btz)$_{2}$(NCS)$_{2}$ (btz = 5,5$^{\prime }$,6,6$^{\prime}$-tetrahydro-4\textit{H},4$^{\prime}$\textit{H}-2,2$^{\prime }$-bi-1,3-thiazine), and Fe(bpz)$_{2}$(bipy) (bpz = dihydrobis(1-pyrazolil)borate, and bipy = 2,2$^{\prime}$-bipyridine). All molecular geometries are taken from the X-ray experimental data and assumed to be frozen. The unit cell dimensions and angles, positions of the centers of masses of molecules, and the orientations of molecules corresponding to the minimum energy at 1 atm and 1 GPa are calculated. The optimized crystal structures are in a good agreement with the experimental data. Sources of the residual discrepancies between the calculated and experimental structures are discussed. The intermolecular contributions to the enthalpy of the spin transitions are found to be comparable with its total experimental values. It demonstrates that the method of atom-atom potentials is very useful for modeling organometalic crystals undergoing the spin transitions

За кадры. 1980. № 67 (2291)

Могучая поступь коммунизма / И. К. ЛебедевОпыт в союзе с молодостью / С. АлександровЭВМ и учебный процессС позиции качества / В. ШкаликовВидеть конкретную цель / М. ИвановаСохранить звание / [беседа с] А. ЛошкаревУрок не пройдет даром / В. МашничПреподаватель: методист или "толкач"? / Б. А. БагинскийЧастичный ремонт произведенДля своевременного комплектования команд / Б. М. ПлотниковЕсли вы покидаете общежитие / Т. БорисоваВниманию любителей "Спортлото"Увлеченность / Г. ВенделеваКниги - победители конкурса / Л. Н. ОнищукПридется подчиниться"Бал - маскарад" или неряшливость? / С. СаксНавстречу съезд

Multipole Model for the Electron Group Functions Method

Electron groups provide a natural way to introduce local concepts into quantum chemistry, and the wave functions based on the group products can be considered as a framework for constructing efficient computational methods in terms of “observable ” parts of molecular systems. The elements of the group wave functions (electronic structure variables) can be optimized by requiring the number of operations proportional to the size of the molecule. This directly leads to computational methods linearly scaling for large molecular systems. In the present work we consider a particular case of such a wave function implemented for the semiempirical NDDO Hamiltonian. The electron groups are expressed in terms of optimized atomic (hybrid) orbitals with chemical bonds described by geminals and the delocalized groups described by Slater determinants (with or without spin restriction). This scheme is very fast by itself but its speed is considerably limited by the computations of the interatomic Coulomb interactions. Here we develop a consistent method based on group functions which uses the multipole scheme for interatomic interactions. The explicit usage of the atomic multipoles makes the method extremely fast, although the numerical efficiency is largely achieved due to the local character of the electron groups involved. We discuss numerical characteristics of the new method as well as its possible parametrization. We apply this method to study dodecahedral water clusters with hydrogen fluoride substitution and base the analysis on the exhaustive calculation of all symmetry-independent hydrogen-bond networks. 1