The effect of host structure on the selectivity and mechanism of intramolecular Prins reactions is evaluated using K12Ga4L6 tetrahedral catalysts. The host structure was varied by modifying the structure of the chelating moieties and the size of the aromatic spacers. While variation in chelator substituents was generally observed to affect changes in rate but not selectivity, changing the host ...

Scopul sintezei cinematice a mecanismelor este determinarea dimensiunilor elementelor componente, în condiţiile impuse prin mişcările unor puncte sau elemente. Rezolvarea unei astfel de probleme se reduce la rezolvarea unui sistem de ecuaţii neliniare. Ca urnare, problemele de sinteză cinematică nu au soluţii unice. Pentru oprimizarea dimensiunilor unui mecanism de prehensiune, funcţia obiectiv...

Pattern mat hing me hanisms based on regular expressions are featured in a number of re ent languages for pro essing tree-stru tured data su h as XML. A ompiler for su h a language must address all the familiar problems of pattern optimization in fun tional languages with ML-style algebrai datatypes and pattern mat hing, plus some new ones arising prin ipally from the use of re ursion in patter...

This study investigated the presence of simian vacuolating virus 40 (SV40) deoxyribonucleic acid (DNA) in malignant pleural mesothelioma, non-neoplastic mesothelium and pleural carcinoma metastasis and correlated these data with immunohistochemistry for SV40 viral antigens. The novel Primed In Situ (PRINS) method was applied to detect the presence of SV40 DNA in situ in tissue sections of malig...

A composição química do óleo essencial das folhas e flores de dois acessos de Ocimum selloi Benth., cultivados na Universidade Fed eral de Viçosa foi analisada. Para o acesso A o componente prin ci pal foi identificado como estragol, o qual representa 94,95% e 92,54% do óleo das folhas e das flores, respectivamente. O óleo obtido das folhas e flores do acesso B é constituído de 65,49% e 66,18% ...

Allocation problems are one of main problem targets to apply today s agent based com puting They can be found in a large specter do mains ranging from production task scheduling to resource allocation or distribution problems How ever there are cases where agents even being au tonomous do not decide what to do without hu man intervention and decision Most of these cases are concerning with econ...

In această lucrare sunt prezentate principiile de funcţionare pentru câteva structuri elementare de choppere de tensiune alternativă. Datorită avantajelor lor, acestea pot fi utilizate într-un număr mare de aplicaţii industriale. Sunt prezentate două tipuri de aplicaţii. Prima aplicaţie o reprezintă stabilizatoarele moderne de tensiune obţinute prin asocierea structurilor elementare cu transfor...

We successfully carried out Prins-type polymerization for the first time to prepare 4-fluorinated tetrahydropyran-containing polymers in a highly stereoselective manner.

http://dvr.sagepub.com/content/3/1/26 The online version of this article can be found at: DOI: 10.3132/dvdr.2006.003 2006 3: 26 Diabetes and Vascular Disease Research Manuela Good, Felicity M Newell, Larisa M Haupt, Jonathan P Whitehead, Louise J Hutley and Johannes B Prins influence of BMI and adipose distribution −− tissue TNF and TNF receptor expression and insulin sensitivity in human oment...

Se pot obţine prototipuri de, aproape, orice complexitate geoemtrică, într-un timp, relativ scurt, prin Prototipare Rapdă, tehnologia de fabricare abordată fiind cea a fabricării “aditive”. Lucrarea evidenţiază importanţa tehnologiei de prototipare rapidă, prin imprimare cu jet,”Ink-Jet Printing”, în design-ul unui reper component al unui produs foarte important şi scump. S-a obţinut prototipul...