Search results for "formal"
showing 10 items of 1654 documents
Umsetzungen an höhermolekularen, molekulareinheitlichen phenol-formaldehyd-kondensaten
1960
An in eindeutiger Synthese und im praparativen Masstab zuganglich gewordenen hohermolekularen, molekulareinheitlichen Phenol-Formaldehyd-Kondensaten (Mol.-Gew. bis zu 1500) wird die Acetylierung, die Umsetzung mit Diphenylcarbamidsaure-chlorid zu Poly-[N-diphenyl-]urethanen und mit Formaldehyd und Dimethylamin zu MANNICH-Basen untersucht. Bei den zwei ersten Umsetzungen wird mit Hilfe der Elementaranalyse bzw. der Acetylbestimmung sowie der UR-Spektren zu unterscheiden versucht, ob alle Hydroxygruppen einer Molekel umgesetzt werden konnen. Die Elementaranalysen der erhaltenen MANNICH-Basen zeigen, das eine vollstandige Einfuhrung von Endgruppen (kettenanaloge Umsetzung) gelungen ist. Higher…
Stufenweise Darstellung von Cyclo{quater[(5-alkyl-2-hydroxy-1,3-phenylen)methylen]}en und ihr Vergleich mit linearen phenolischen Mehrkernverbindungen
1978
The stepwise syntheses of cyclo{quater[(5-alkyl-2-hydroxy-1,3-phenylene)methylene]}s (5) are described and compared with a one-flask reaction procedure. The structures of the cyclic compounds 5 are analytically confirmed and their properties were compared with those of linear phenol formaldehyde condensates which have very similar structures and molecular weights.
Die unter dem einfluß geringer mengen an natriumionen verlaufende schmelzkondensation von 2.6-dihydroxymethyl-4-methylphenol
1970
Die wahrend der bei 130°C verlaufenden Schmelzkondensation von 2.6-Dihydroxy-methyl-4-methylphenol (I) bestimmten Gewichtsverluste und Mengen von abgespaltenem Formaldehyd waren um so groser, je hoher der analytische Natriumgehalt der Verbindung lag; dieser wurde durch Beimischen des Natriumphenolats von I im Bereich von 0,01 bis 3,0 Gew.-% Natrium eingestellt. Die in der Literatur angegebenen, stark voneinander abweichenden Mengen von abgespaltenem Formaldehyd sind wahrscheinlich durch unkontrollierte Natriumgehalte von I bedingt; sie konnen aus dem Natriumsalz stammen, uber das Verbindung I gewohnlich hergestellt wird. The losses in weight and the amounts of formaldehyde split off, which …
1965
Bei der Polymerisation von Trioxan bei 70°C in der Schmelze mit HClO4 · H2O als Initiator nimmt die Bruttopolymerisationsgeschwindigkeit exponentiell mit steigender Wasserkonzentration ab; gleichzeitig nimmt die Lange der Induktionszeit entsprechend zu. Die Retardierung durch Wasser wird auf eine Hydratation aktiver Zentren zuruckgefuhrt. Wasser ist ein wirkungsvoller Polymerisationsubertrager; seine relative Ubertragungskonstante betragt bei 25°C in Methylenchlorid ca. 2,6. Jedoch werden die Verhaltnisse durch die Bildung von Methylenglykol aus Wasser und Formaldehyd kompliziert. In polymerization of trioxane in the melt at 70°C. with HClO4 · H2O as initiator the rate of polymerization dec…
Città informali, città dell'esclusione: responsabilità disciplinari nella ricerca e nella pratica
2011
Il contributo affronta il tema della città informale cercando di comprendere in che modo sia possibile affrontare le nuove sfide poste dalla città dei PVS e, più in generale dalla città contemporanea, che manifesta un sempre più accentuato divario fra gli have e gli have nots.
BALANCE PROPERTIES AND DISTRIBUTION OF SQUARES IN CIRCULAR WORDS
2010
We study balance properties of circular words over alphabets of size greater than two. We give some new characterizations of balanced words connected to the Kawasaki-Ising model and to the notion of derivative of a word. Moreover we consider two different generalizations of the notion of balance, and we find some relations between them. Some of our results can be generalized to non periodic infinite words as well.
Turing's Error-revised
2016
Many important lines of argumentation have been presented during the last decades claiming that machines cannot think like people. Yet, it has been possible to construct devices and information systems, which replace people in tasks which have previously been occupied by people as the tasks require intelligence. The long and versatile discourse over, what machine intelligence is, suggests that there is something unclear in the foundations of the discourse itself. Therefore, we critically studied the foundations of used theory languages. By looking critically some of the main arguments of machine thinking, one can find unifying factors. Most of them are based on the fact that computers canno…
An Optimized Architecture for CGA Operations and Its Application to a Simulated Robotic Arm
2022
Conformal geometric algebra (CGA) is a new geometric computation tool that is attracting growing attention in many research fields, such as computer graphics, robotics, and computer vision. Regarding the robotic applications, new approaches based on CGA have been proposed to efficiently solve problems as the inverse kinematics and grasping of a robotic arm. The hardware acceleration of CGA operations is required to meet real-time performance requirements in embedded robotic platforms. In this paper, we present a novel embedded coprocessor for accelerating CGA operations in robotic tasks. Two robotic algorithms, namely, inverse kinematics and grasping of a human-arm-like kinematics chain, ar…
Implementation and evaluation of medical imaging techniques based on conformal geometric algebra
2020
Medical imaging tasks, such as segmentation, 3D modeling, and registration of medical images, involve complex geometric problems, usually solved by standard linear algebra and matrix calculations. In the last few decades, conformal geometric algebra (CGA) has emerged as a new approach to geometric computing that offers a simple and efficient representation of geometric objects and transformations. However, the practical use of CGA-based methods for big data image processing in medical imaging requires fast and efficient implementations of CGA operations to meet both real-time processing constraints and accuracy requirements. The purpose of this study is to present a novel implementation of …
L’evoluzione del formalismo negoziale nei contratti bancari e finanziari
2022
Il lavoro traccia le principali linee evolutive in tema di forma dei contratti bancari e finanziari, concentrandosi sui più recenti orientamenti della Corte di cassazione italiana. Si evidenzia, quindi, un progressivo cambio di atteggiamento della giurisprudenza volto a mitigare la rigidità dei vincoli formali interpretandoli in chiave funzionale.