Modeling of electrons and photons beams of linear (planar) accelerator Elekta Synergy in modelling system PLUNC

The article presents the experience of creating a model of beam in the non-commercial 3D Plan-UNC radiation treatment planning system (PLUNC). The results of dosimetry for electron and photon beams of the Elekta Synergy linear accelerator are presented

6-(4-Meth­oxy­phen­yl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde

The 4-meth­oxy­phenyl residue in the title compound, C21H19NO2, is oriented at a dihedral angle of 54.6 (5)° with respect to the phenyl ring and at a dihedral angle of 52.5 (8)° with respect to the pyrrole ring of the pyrrolizine system. The phenyl ring is oriented at a dihedral angle of 36.2 (5)° with respect to the pyrrole ring. The meth­oxy group makes a C—C—O—C torsion angle of 3.8 (9)° with the attached benzene ring

Extractability and Intracellular Localisation of Urea Cycle Enzym es from Rat Liver

Peer Reviewe

6-(4-Chloro­phen­yl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde

The 4-chloro­phenyl residue in the title compound, C20H16ClNO, is oriented at a dihedral angle of 53.6 (3)° towards the phenyl ring and 42.0 (9)° towards the pyrrole ring of the pyrrolizine template. The phenyl ring is oriented at a dihedral angle of 45.4 (4)° towards the pyrrole ring

2′-Hy­droxy­methyl-1′-(4-methyl­phen­yl)-2′-nitro-1′,2′,5′,6′,7′,7a′-hexa­hydro­spiro­[indoline-3,3′-pyrrolizin]-2-one

In the title compound, C22H23N3O4, the tolyl ring is almost perpendicular [83.86 (7)°] to the best plane through the eight atoms of the pyrrolizidine ring system. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯O hydrogen bond. The crystal packing features inversion dimers with R 2 2(8) motifs linked by pairs of N—H⋯O hydrogen bonds

Радиографический метод контроля сварных швов трубопроводов

Обнаружение дефектов сварных соединений является одной из основных задач неразрушающего контроля, применяемого для диагностики технического состояния трубопроводов различного назначения. Среди методов неразрушающего контроля широкое распространение получил радиографический метод. Для обработки изображений, полученных радиографическим методом, и обнаружения дефектов сварки, используются различные алгоритмы. Одним из перспективных алгоритмов обработки изображений является алгоритм, основанный на методе нейронной сети.Detection of defects in welded joints is one of the main tasks of non-destructive testing used for diagnostics of the technical condition of pipelines for various purposes. Among the methods of nondestructive testing, the radiographic method is widely used. For processing images obtained by radiographic method, and the detection of welding defects, various algorithms are used. One of the promising algorithms for image processing is an algorithm based on the neural network method

Future challenges in colloid and interfacial science

This article deals with topics where I expect special future challenges, exemplifying these by experiments out of my own department. One area where I expect large progress also in view of many technical developments in the past concerns the understanding of the structure of fluid interfaces at the atomic level. It is shown by non-linear optical spectroscopies that the free water surface is ice-like and can be “liquefied” by ion adsorption. X-ray fluorescence from the interface demonstrates that ion binding is very specific which cannot be explained by existing theories. A second major area are nonequilibrium features, and one of the old and new ones here is nucleation and growth. This presentation concentrates on effects produced by ultrasound, a well-defined trigger of gas bubble formation. It exhibits high potential for chemistry at extreme conditions but with a reactor at normal conditions. It has special importance for treatment of surfaces that can be also manipulated via controlled surface energies. A third area will concern complex and smart systems with multiple functions in materials and biosciences. As next generation, I anticipate those with feedback control, and examples on this are self-repairing coatings

Tellurium(II) dialkanethiolates: n(p)(S)-sigma*(Te-S ') orbital interactions determine the Te-125 NMR chemical shift, and the molecular and crystal structure

Fleischer H, Mitzel NW, Schollmeyer D. Tellurium(II) dialkanethiolates: n(p)(S)-sigma*(Te-S ') orbital interactions determine the Te-125 NMR chemical shift, and the molecular and crystal structure. EUROPEAN JOURNAL OF INORGANIC CHEMISTRY. 2003;(5):815-821.Tellurium(II) dimethanethiolate, Te(SMe)(2), and tellurium(II) diethanethiolate, Te(SEt)(2), were synthesized by reaction of TeO2 and Te(OiPr)(4) with HSMe and HSEt, respectively. In the solid state, Te(SMe)(2) exhibits a cis-conformation of the methyl groups with respect to the TeS2 plane - an unprecedented situation for nonfunctionalized organotrichalcogenides - whereas Te(SEt)(2) shows a trans-conformation. Ab initio calculations performed for Te(SMe)(2) and Te(SEt)(2) show that the cis- and trans-conformers represent minima on the potential energy surface and are stabilized by intramolecular pi-type n(S)-sigma* (Te-S') orbital interactions. In the solid state, the molecules of each compound are associated through two centro-symmetric Te2S2 units with two of their neighbors, resulting in tetracoordinate Te atoms with distorted trapezoidal configurations. While the intermolecular Te...S distance increases in the sequence R = Me < Et < iPr < tBu, the length of the covalent Te-S bond decreases in the same order, a result attributed to intermolecular sigma-type n(p)(S)-sigma*(Te-S') orbital interactions. The Te-125 NMR chemical shift of Te(SR)(2) largely depends on R (R = Me, Et, iPr, tBu) and shows a nearly linear correlation with the first ionization energy of the corresponding thiol HSR. Ab initio calculations of the Te-125 NMR shifts for the model compound Te(SH)(2) (C-2 symmetry) reveal that it also depends strongly on the HSTeS torsion angle. These results can be explained by a model in which pi-type n(p)(S)- sigma*(Te-S') and n(p)(Te)-sigma*(S-H) orbital interactions determine the paramagnetic shielding of the tellurium nucleus. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 2003)