Search results for "LOAD"
showing 10 items of 1967 documents
Zur Regiochemie von [4 + 2]-Cycloadditionen mit Methylpyrano[3,4-b]indol-3-onen und unsymmetrischen Dienophilen
1989
Die methylierten Pyrano[3,4-b]indol-3-one 1a, 1b reagieren mit acyclischen, unsymmetrischen CC-Dienophilen nach einer Diels-Alder-Reaktion/CO2-Extrusion zu selektiv funktionalisierten Carbazolen 2. In Abhangigkeit von der Struktur der Reaktionspartner wird keine oder geringe bis hohe Regioselektivitat festgestellt. Diethylmesoxalat reagiert mit 1a, 1b regioselektiv zu neuen 2,3-difunktionalisierten Indolen 4a, 4b, die aus einer regiokontrollierten [4 + 2]-Cycloaddition und Cycloreversion resultieren, wobei Pyrano[3,4-b]indoldicarbonsaure-diethylester 3a, 3b als Intermediate auftreten durften. Regiochemistry of [4 + 2] Cycloadditions with Methylpyrano[3,4–b]indol-3-ones and Unsymmetric Dieno…
The reactivity of 2-vinylindoles with dimethyl acetylenedicarboxylate
1984
Abstract The overall rates of reaction of 1-substltuted-1- (1-methyl-2-indolyl)ethenes with dimethyl acetylenedicarboxylate are considerably lower than those of the corresponding 2-vinyl- pyrroles. Steric interaction between the N-methyl group on the indole ring and the 1-substituent on the ethenyl group prevents the diene system adopting a coplanar cisoid configuration and, thereby, inhibits the π4 + π2 cycloaddition reaction of the system with dimethyl acetylenedicarboxylate. Under such conditions, the indolylethene preferentially undergoes a Michael addition reaction at the 3-position. The π4 + π2 cycloaddition reaction is promoted at elevated temperatures. No evidence was found for a Co…
ASPECTS OF INEQUALITY IN THE CONTEXT OF EMPLOYMENT OF PRE-SCHOOL TEACHERS IN LATVIA
2020
Policy-making in education involves social agents at national, municipal and institutional levels. National regulations and financial capacity of municipalities determine working conditions of teachers and employment aspects at all levels of the education system. For several years, discussions have been taking place in Latvia involving employers of education sector and policy makers on tackling inequalities in pay and workload principles for pre-school teachers. Situation of the pre-school teachers varies across municipalities and is affected by their financial opportunities to sustain educational institutions and ensure teachers’ salaries. In 2019, Latvian Trade Union of Education and Scie…
Teletrabajo docente durante el confinamiento por COVID19 en Argentina. Condiciones materiales y perspectivas sobre la carga de trabajo, la responsabi…
2021
En Argentina las medidas para enfrentar la pandemia del COVID 19 incluyeron la suspensión de las clases presenciales en todos los niveles educativos y la implementación de una política de continuidad educativa. El objetivo de este artículo es analizar, por un lado, cuáles han sido las condiciones materiales y temporales del teletrabajo docente al inicio del confinamiento. Por el otro, examina las percepciones docentes respecto del grado de participación en la toma de decisiones respecto de su tarea remota mediada por TIC; la carga mental que el teletrabajo forzado implicó; y su responsabilidad frente al sostenimiento de las trayectorias educativas de sus estudiantes. Nuestro abordaje se nut…
Diffusive Modeling of Aggradation and Degradation in Artificial Channels
2008
The unsteady flow and solid transport simulation problem in artificial channels is solved using a three-equation model, coupled with a local erosion law. The three equations are the water mass and momentum balance equations, as well as the total solid load balance equation. It is shown that even during severe hydrological events inertial terms can be neglected in the momentum equation without any substantial change in the solution sought. Empirical equilibrium formulas were used to estimate the solid load as a function of the flow variables. Local erosion, due to the scour generated at the jump between two channels connected at different bottom elevations, was estimated adapting a literatur…
Information management and complementary alternative medicine: the anatomy of information about CAMs through PubMed
2013
In recent years, there has been a growing interest about complementary and alternative medicine (CAM), and the use of CAM interventions has become more common among people. For these reasons, health professionals must be able to effectively manage information in this field of knowledge according to an evidence-based point of view. This study assessed the anatomy of the available information about CAMs using PubMed, to give practical instructions to manage information in this field. We also analyzed the anatomy of information according to each alternative medicine branch, narrow and broad search methods, subset filters for indexed-for-Medline and non-indexed citations, and different publicat…
Cognitive and Affective Consequences of Information and Choice Overload
2021
When interviewed in 1992 in Pittsburgh, Pennsylvania, the Nobel laureate Herbert Simon described a paradox at the heart of living in an economy that made every effort to design and produce ever more “choice alternatives” but that simultaneously allocated very little energy to encouraging people to devote the attention and time actually required to choose. He gave the example of a decision to buy a new house, commenting: “Before you even start the choice process, somebody has presented you with this, and this, and this house” (UBS, 1992). The overabundance of alternatives was lamented by Simon in 1992, when computing power was slower. It is all the more alarming in the modern and constantly …
An Iterative Information Retrieval Approach from Social Media in Crisis Situations
2019
During to past few years, social media have gained a pivotal role in crisis communication. Its usage has ranged from informing the public about the status of a crisis and what precaution need to be taken, to family members checking on the safety of loved ones. Despite the widespread use of social media in crises situations and the clear potential benefit from collecting potential critical information from social media, emergency management services (EMSs) are still reluctant to use social media as a source of information to improve their situational awareness. One of the reasons for the reluctance is that crises management are typically overloaded with information. Adding social media will …
The relationship between medical students’ media use and learning progress
2021
The acquisition of warranted domain-specific knowledge is essential for practical work in medicine. The medical field, however, suffers from 'information overload', and students and physicians rely...
The Results of Changing the Current Solution Concept of Universal Motor Gear Reducers with Helical Gears
2021
By analysing and comparing the existing solutions of universal gear reducers with helical gears of the leading manufacturers, it can be noticed the effort to increase the load capacity of the gear reducer within the same axis height. In this way, the manufacturers can offer smaller (cheaper) gear reducers, as well as to simultaneously increase the values of the largest gear ratios. This concept enables the offer of lower-stage (cheaper) gear reducers with higher gear ratios in certain segments of gear ratios. By these efforts, it is reached the maximum, but the further increase is possible only by changing the current concept of universal gear drives. Within this paper, it is given an overv…