Laserspektroskopische Bestimmung absoluter Konzentrationen von CH- und CN-Radikalen in Niederdruck-Wasserstoffflammen während der Verbrennung von Graphit

Ziel dieser Arbeit war die Charakterisierung reaktiver Spezies wie sie bei der Verbrennung von Kohlenstoff (im einfachsten Fall: Graphit) unter dem Einfluß einer Niederdruck-Wasserstoffflamme variabler Stöchiometrie auftreten. Zur Messung der CN-Radikale wurden der Wasserstoffflamme definierte Mengen NO beigemischt, die sich im weiteren Verlauf zu CN-Radikalen umsetzten. Mit Hilfe der berührungsfreien linearen laserinduzierten Fluoreszenzspektroskopie (LIF) konnten räumlich aufgelöste 2-D-Konzentrationsprofile von CH- und CN-Radikalen gemessen werden, ohne die chemisch-physikalischen Gasphasenprozesse zu beeinflussen. Unter Einsatz der Ramankalibration mit Stickstoff, der Messung effektiver Lebensdauern und der Gasphasentemperaturbestimmung aus aufgelösten Rotationsspektren, wurden erstmals absolute Konzentrationen von CH- und CN-Radikalen für verschiedene Verbrennungsbedingungen ermittelt

Infrared properties of SiC particles

We present basic laboratory infrared data on a large number of SiC particulate samples, which should be of great value for the interpretation of the 11.3 micron feature observed in the spectra of carbon-rich stars. The laboratory spectra show a wide variety of the SiC phonon features in the 10-13 micron wavelength range, both in peak wavelength and band shape. The main parameters determining the band profile are morphological factors as grain size and shape and, in many cases, impurities in the material. We discovered the interesting fact that free charge carriers, generated e.g. by nitrogen doping, are a very common characteristics of many SiC particle samples. These free charge carriers produce very strong plasmon absorption in the near and middle infrared, which may also heavily influence the 10-13 micron feature profile via plasmon-phonon coupling. We also found that there is no systematic dependence of the band profile on the crystal type (alpha- vs. beta-SiC). This is proven both experimentally and by theoretical calculations based on a study of the SiC phonon frequencies. Further, we give optical constants of amorphous SiC. We discuss the implications of the new laboratory results for the interpretation of the spectra of carbon stars.Comment: 17 pages, 12 figures. To appear in A&

In vivo probing of SECIS-dependent selenocysteine translation in Archaea

Cotranslational insertion of selenocysteine (Sec) proceeds by recoding UGA to a sense codon. This recoding is governed by the Sec insertion sequence (SECIS) element, an RNA structure on the mRNA, but size, location, structure determinants, and mechanism differ for Bacteria, Eukarya, and Archaea. For Archaea, the structure–function relation of the SECIS is poorly understood, as only rather laborious experimental approaches are established. Furthermore, these methods do not allow for quantitative probing of Sec insertion. In order to overcome these limitations, we engineered bacterial β-lactamase into an archaeal selenoprotein, thereby establishing a reporter system, which correlates enzyme activity to Sec insertion. Using this system, in vivo Sec insertion depending on the availability of selenium and the presence of a SECIS element was assessed in Methanococcus maripaludis. Furthermore, a minimal SECIS element required for Sec insertion in M. maripaludis was defined and a conserved structural motif shown to be essential for function. Besides developing a convenient tool for selenium research, converting a bacterial enzyme into an archaeal selenoprotein provides proof of concept that novel selenoproteins can be engineered in Archaea

OPTIONS FOR DESIGNING STABLECOINS AND CENTRAL BANK DIGITAL CURRENCIES

Stablecoins are cryptographic digital currencies that follow a fixed or target exchange rate regime. The objective of this paper is to introduce for the IS community the concept of stablecoins in their various forms and features and investigate their relationship to Central bank Digital Currencies. This seems timely as several central banks are considering launching a cryptographic currency. The central bank digital currency (CBDC) trend gained traction following the emergence of a number of privately-issued stablecoins. This paper distinguishes amongst thirteen design dimensions that are relevant for decision makers launching stablecoins and central bank digital currencies using distributed ledger technologies. We explain each dimension in the context of prominent CBDC and stablecoin projects. Finally, future areas of CBDC and stablecoin research are elaborated upon. This research is one of the first attempts to combine information systems and monetary policy research to explain the new phenomena of stablecoin and CBDC

A Framework for Clarifying "Participation" in Participatory Research to Prevent its Rejection for the Wrong Reasons

Participatory research relies on stakeholder inputs to obtain its acclaimed benefits of improved social relevance, validity, and actionability of research outcomes. We focus here on participatory research in the context of natural resource management. Participants' acceptance of participatory research processes is key to their implementation. Our first assumption is that this positive view and acceptance of participation in research processes is a public good for the whole participatory research community. We also assume that the diversity of participatory forms of research is rarely considered by potential participants when they make their decisions about whether or not to participate in a proposed process. We specifically address how to avoid stakeholders' reluctance to be involved in participatory research projects based on disillusion with past experiences. We argue that the disappointment experienced by stakeholders and other participants (i.e., researchers and policy makers) can be avoided by being upfront and precise about how participation will be implemented, and what kind of involvement is expected from participants. Such a collective effort from the research community can also clarify the variety of possible implementations for potential participants. Building on earlier efforts to characterize and categorize the diversity of participatory research approaches, we develop a conceptual analytic procedural framework to make participants' roles explicit in the implementation of different participatory research processes. This framework consists of three facets: (1) the flows of information among participants and the control over these flows for each step in a process, i.e., who will be expected to produce information, who will use this information, and who will receive the results; (2) the timing of the involvement of participants in the different steps of the research process, and the framing power that is associated with each process step; and (3) the organization of communication among participants for each information flow, i.e., in what configuration (bilaterally or as a group, mediated or face to face) the interactions among researchers, stakeholders, and policy makers will take place. This framework can accommodate a wide variety of research methods, and highlights exactly how participants are involved in research processes. We are prescriptive in dealing with the need to be procedurally explicit when engaging in participatory research. We anticipate that using this framework will lead to more thoughtful acceptances or refusals to participate in proposed research processes. Our framework is based on various experiences with participatory research. It is intended to be used from the very beginning of a participatory research process as a conceptual guide for researchers. We suggest a protocol to transform it into more practical guidelines for communicating about upcoming participatory research processes. The leader of such processes should propose at each key stage an explicit, yet adaptive, plan for the following stages. This plan should also specify in what ways participants will be involved, and how the plan itself can be questioned and revised

CONVENÇÃO DE HAIA SOBRE ADOÇÃO E OS REFLEXOS DE DIREITO INTERNACIONAL

O presente artigo tem como objeto a adoção internacional de crianças e de adolescentes. O seu objetivo é demonstrar aos leitores o resultado da Convenção Internacional de Haia, tendo como referencial o aspecto de direito internacional.Para a composição deste artigo, foi utilizado o método indutivo de pesquisa e de análise dos dados, operacionalizando técnicas de Referente, de Categoria, de Conceitos Operacionais e de Pesquisa Bibliográfica.

Determinação do índice de segurança potencial em rodovias pedagiadas e não pedagiadas do Rio Grande do Sul

O presente trabalho consiste na determinação do Índice de Segurança Potencial (ISP), é um procedimento indicado para a análise de rodovias brasileiras, e tem finalidade de retratar as condições de segurança de segmentos rodoviários, resultando em um perfil dos trechos inspecionados, sendo possível identificar os que apresentam maiores problemas nas condições de segurança e a característica física que causa essas deficiências. A metodologia baseia-se em fazer uma avaliação de campo das rodovias pedagiadas RSC-453 e BR-386, e não pedagiadas ERS-413 e BR-116, utilizando uma planilha de inspeção que contém 34 características principais a serem analisadas, como buracos na pista, qualidade da sinalização horizontal e vertical entre outros, dispondo também, de um gabarito de notas. A partir dos resultados obtidos, foi possível observar que as rodovias variaram entre “Potencialmente razoavelmente seguro”, “Potencialmente seguro” e “Potencialmente inseguro”, o ISP global da RSC-453 foi de 6,95, a BR-386 de 7,39, a ERS-413 de 5,07 e a BR-116 de 5,11. Com os resultados, percebe-se que nas rodovias pedagiadas existe um maior investimento em manutenção e conservação do que nas não pedagiadas

Projeto para implantação de área verde urbana com recuperação de área de preservação permanente no município de Três de Maio - RS

Orientador: Prof. Dr. Alessandro Camargo ÂngeloCoorientadora: Profª Dra. Karen Koch Fernandes de SouzaArtigo (Especialização) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Curso MBA em Gestão Ambiental.Resumo: Este trabalho visa a apresentação de um projeto para a implantação de uma área verde urbana no município de Três de Maio/RS com o intuito de preservar e recuperar o local, e ainda, fazer com que o mesmo possa ser utilizado pela população para lazer e recreação. O objetivo é propor a revegetação de pelo menos 70% da área com espécies nativas locais, e em meio a este espaço, inserir elementos que possibilitem a realização de atividades físicas, de lazer e recreação, como pista de caminhada, trilhas, pracinha e bancos para descanso. Além disso, o local permitirá a realização de atividades de educação ambiental, com o auxílio de placas informativas que serão instaladas pela área, buscando conscientizar estudantes das escolas do município, a comunidade do bairro no qual o espaço está inserido, e a população em geral, chamando sua atenção para a importância de grandes temas relacionados ao meio ambiente: água, resíduos, energia, solo e biodiversidade. Um dos limites da área, a qual pertence ao município, se dá com o córrego Quarainzinho, do qual irá se propor a recuperação da área de preservação permanente