277 research outputs found
Prophets and followers in Batak Millenarian responses to the colonial order : parmalim, na siak bagi and parhudamdam, 1890-1930
The thesis examines three related millenarian movements
among the Batak: Parmalim, Na Siak Bagi and Parhudamdam.
During the latter part of the 19th century, the Toba
Batak area in north Sumatra was exposed to Euroean influence
after the defeat of the traditional power symbol, Si Singa
Mangaraja. Millenarian expectations began after Batak people
were obliged to recognize the superiority of European power,
yet were in many cases not satisfied with the new order. The
Parmalim movement was started by Guru Somalaing, a datu
(magician), who claimed to be able to gain access to the
source of European power (Jehova) while retaining the essence
of Toba Batak values. He gained followers mainly from places
where the people were newly exposed to European influence and
still retained their indigenous value systems. Parmalim
followers believed that German missionaries working in these places were really Batak divine
kings and that some day these kings and Raja Rum (identified with an Italian traveller
Modigliani) would drive the Dutch away
Grafting polyacrylates from carbohydrates by ATRP and formation of nanoparticles for advanced drug delivery
The present thesis describes synthesis and characterization of graft copolymers from carbohydrates and formulation of nanoparticles(NP)s for drug carrier application. Side chains were produced grafting from carbohydrate based macroinitiators via Atom Transfer Radical Polymerization (ATRP). Firstly, hydrophobic homo-, random- and block-copolymer side chains were grafted from a beta-Cyclodextrin core, followed by starch as a core. Monomer conversions up to 80% were achieved in most cases and well controlled polymers were obtained. Ni(II) triphenylphosphine complexes were found to be catalysts superior to the well known Cu(I) complexes, because they can be removed much easier from the product after polymerization.
NPs prepared by the emulsion-diffusion technique showed particle sizes of <200 nm, uniform shape and narrow size distribution (PDI<0.1). Not only the production parameter of NPs but also the chemical properties of the polymer influence the stability and size distribution of NPs. Especially the hydrophobicity of polymers and the composition of the arm of polymers (block or random) have a big influence on the stability and PDI of NPs. Since cell viabilities remain unaffected by these NPs, they are good candidates for the delivery of drugs. In conclusion, hydrophobically modified carbohydrate derivatives have a potential to serve as a new platform for biodegradable and biocompatible nano carriers.Die vorliegende Arbeit beschreibt die Synthese und Charakterisierung von Pfropf- Copolymeren aus Kohlenhydraten und Polyacrylaten, sowie die Formulierung von Nanopartikeln(NP) als Trägermaterialien für Arzneistoffe. Die Seitenketten wurden mittels Atom Transfer Radical Polymerization (ATRP) an die Kohlenhydrate anpolymerisiert. Zunächst erfolgte die Synthese von hydrophoben Pfropfpolymeren mit Homo-, Random- und Block-Copolymer-Seitenketten ausgehend von beta- Cyclodextrin als Kern, anschließend wurde auch Stärke als Kern verwendet. Hierbei wurden unter Monomerumsätzen von mehr als 80% definierte Polymere erhalten. Ni(II)-Komplexe waren den bekannten Cu(I)-Katalysatoren überlegen, da sie nach der Polymerisation leichter entfernt werden können.
Die mittels Emulsions-Diffusions-Technik hergestellt NP, besitzen einheitliche Formen und Größen (ca. 200 nm) und eine enge Größenverteilung. Hierbei waren nicht nur die Parameter bei der NP-Herstellung, sondern auch die chemischen Eigenschaften des Polymers wichtig. Besonders die Hydrophobie der Polymere und die Zusammensetzung der Seitenketten (Block- oder Random) haben einen großen Einfluss auf die Stabilität und die Größenverteilung der NP. Da die Zellviabilität durch die NP nicht beeinträchtigt wird, eignen sie sich für pharmakologische Anwendungen. Die hydrophob modifizierten Kohlenhydrat-Derivate stellen somit eine viel versprechende neue Plattform für biologisch abbaubare und biokompatible Nanocarrier dar
Post-disaster long-term recovery and reconstruction. Haiti after the earthquake in january 2010
All over the world, natural hazards associated to climate change effects are increasing in frequency and threatening urban development dynamics while increasing human losses and economic expenditure. The objective of this paper is to investigate how post-disaster recovery and reconstruction should be addressed when associated with a scenario of urban poverty, lack of governance and social inequalities that can affect or restrict the capacity of a low-income country like Haiti to respond to natural hazards. Keywords: Disaster. Post-disaster. Recovery. Reconstruction. Haiti
Post-disaster long-term recovery and reconstruction. Haiti after the earthquake in january 2010
All over the world, natural hazards associated to climate change effects are increasing in frequency and threatening urban development dynamics while increasing human losses and economic expenditure. The objective of this paper is to investigate how post-disaster recovery and reconstruction should be addressed when associated with a scenario of urban poverty, lack of governance and social inequalities that can affect or restrict the capacity of a low-income country like Haiti to respond to natural hazards.
Keywords: Disaster. Post-disaster. Recovery. Reconstruction. Haiti
Proposta de Automatização do Método Leonês para Cálculo da Tarifa do Transporte Público Urbano em Visual Basic for Applications (VBA)
Os métodos de cálculo de tarifas do transporte por ônibus utilizados no Brasil, em sua grande parte, estão obsoletos, sendo necessárias novas formas de se calcular o valor das tarifas. A automatização dos métodos de cálculos faz com que os órgãos competentes e projetistas levem menos tempo com demandas operacionais e possam focar em análises mais profundas sobre os custos do sistema de transporte coletivo urbano. Portanto, este estudo apresenta uma proposta de automatizar um desses métodos de cálculo: o Método Leonês. Tal automatização foi executada no Microsoft Excel através da linguagem de programação própria do software, denominada VBA (Visual Basic for Applications). Por fim, foram obtidos como resultados a planilha final de cálculo, considerações na concepção da planilha e ideias futuras de melhorias possíveis no programa construído
Visualization of Stent Lumen in MR Imaging: Relationship with Stent Design and RF Direction
Magnetic resonance imaging (MRI) visualization of metallic stent lumens is possible if the stent structure
counteracts eddy currents in the lumen induced by the radio frequency magnetic field, B1. To examine the effectiveness of various stent designs in counteracting eddy currents, we anchored eight copper stent models and 2 commercially available nickel-titanium alloy (Nitinol) stents in a gel phantom,
perpendicular or parallel to the direction of B1. A mesh stent lumen showed hypointensity irrespective
of its alignment relative to B1. A solenoid stent lumen showed hypointensity with the stent axis parallel to B1, but it had the same signal intensity as outside the lumen when perpendicular to B1. A Moebius stent lumen showed no signal reduction, irrespective of alignment relative to B1. Lumens of the commercially available stents showed hypointensity regardless of alignment relative to B1. Computer simulation revealed that the signal intensities of the stents corresponded to magnetic flux densities of B1 in the stents, which are modified by the structure of the stent. While in vivo MRI viewing
of a Moebius stent lumen is likely possible regardless of axis alignment, inherent structural weakness
may be problematic. As a more practical choice, the solenoid stent is easier to manufacture and generates no hypointensive signal when the axis is parallel to B0
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