34 research outputs found
Reduced transition probabilities for the gamma decay of the 7.8 eV isomer in Th
The reduced magnetic dipole and electric quadrupole transition probabilities
for the radiative decay of the Th 7.8 eV isomer to the ground state are
predicted within a detailed nuclear-structure model approach. We show that the
presence and decay of this isomer can only be accounted for by the Coriolis
mixing emerging from a remarkably fine interplay between the coherent
quadrupole-octupole motion of the nuclear core and the single-nucleon motion
within a reflection-asymmetric deformed potential. We find that the magnetic
dipole transition probability which determines the radiative lifetime of the
isomer is considerably smaller than presently estimated. The so-far disregarded
electric quadrupole component may have non-negligible contributions to the
internal conversion channel. These findings support new directions in the
experimental search of the Th transition frequency for the development
of a future nuclear frequency standard.Comment: 5 pages, 1 figure, supplementary material is available as pdf with
the source files, v3 includes small corrections to match the published
version, results unchange
The electric quadrupole channel of the 7.8 eV transition
The unique isomeric transition at 7.8 eV in has a
magnetic dipole () and an electric quadrupole () multipole mixing. So
far, the component has been widely disregarded. Here, we investigate the
nuclear physics nature and the impact of the decay channel for the nuclear
coupling to the atomic shell based on the newest theoretical predictions for
the corresponding reduced nuclear transition probabilities. Our results show
that the contribution of the channel is dominant or at least of the same
order of magnitude for internal conversion or electronic bridge transitions
involving the atomic orbitals , and . Notable exceptions are the
internal conversion of the electron and the electronic bridge between the
electronic states and , for which the component dominates by two
to three orders of magnitude. Caution is therefore advised when considering
isomeric excitation or decay via nuclear coupling to the atomic shell, as the
involved orbitals determine which multipole transition component dominates
Assessing the Ability of the Cradle to Cradle Certifiedâą Products Program to Reliably Determine the Environmental Performance of Products
Concepts and tools supporting the design of environmentally friendly products (including materials, goods or services) have increased over the last years. The Cradle to Cradle Certifiedâą Products Program (C2CP) is one of these approaches. In this work, the ability of C2CP to reliably determine the environmental performance of products was analyzed through the application of a criteria-based assessment scheme. Additionally, to compare C2CP with three other already established tools (life cycle assessment, product environmental footprint and material flow analysis), the same criteria-based scheme was applied. Results show that C2CP is not scientifically reliable enough to assure that certified products actually have a good environmental performance. The most relevant shortcoming of C2CP relates to its limited assessment scope, due to the fact that neither the entire life cycle of the product nor all relevant environmental impacts are covered. Based on already established tools and their practical implementation recommendations for increasing the reliability of C2CP are provided
Characterization of the Cradle to Cradle Certifiedâą Products Program in the context of eco-labels and environmental declarations
(1) Background: The Cradle to Cradle Certified⹠Products Program (C2C Certified for short) is a scheme for the certification of products that meet the criteria and principles of the Cradle to CradleŸ design approach. The objective of this paper is to characterize C2C Certified as an instrument for external communication in the context of environmental labeling and declarations. (2) Method: An eco-label characterization scheme consisting of 22 attributes was used to analyze C2C Certified. In addition, it was compared with the established standardization labeling typologies, namely Type I and Type III. This was further illustrated in an example within the building and construction sector. (3) Results: C2C Certified can be classified neither as a Type I, nor a Type III label. The main weaknesses of C2C Certified from a labeling perspective are: the generic, but not product-specific focus of the awarding criteria, the lack of a life cycle perspective, and the incompletely transparent stakeholder involvement procedure. Nevertheless, for certain attributes (e.g., the awarding format), C2C Certified provides practical solutions and goes beyond a Type I eco-label. Substantial similarities between Type III declarations and C2C Certified cannot be identified. (4) Conclusions: The main advantages and shortcomings of C2C Certified from a labeling perspective are pointed out. The approach shows similarities to a Type I eco-label, and efforts toward conformance with the International Organization for Standardization (ISO) labelling standards would result in improving its comparability, recognition, and robustness.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische UniversitÀt Berli
Selection Criteria for Suitable Indicators for Value Creation Starting with a Look at the Environmental Dimension
AbstractThis paper presents a set of selection criteria for identifying indicators for sustainable production of the manufacturing industry. Starting from a condensed overview of over 500 general sustainability indicators, such focussing on sustainable production are discussed, including the three dimensions of sustainability and the indicator qualities. Based on the Collaborative Research Centres (CRC) 1026 Framework and with the understanding that manufacturing industries may differ, the authors suggest to use the ABC judgement method - a semi-quantitative systematic method to prioritize indicators based on expert judgement and supporting evidences - to select core and supplemental indicators. Concise questionnaires considering sustainability targets are used and combined with a scoring system to support the decision process. The method can use either top-down indicators (i.e. on the impact level e.g. acidification, climate change) or bottom-up indicators (i.e. on inventory level e.g. energy consumption, recycling rate, volume or weight of solid waste/hazardous waste). Proof of concept of the proposed approach in a life cycle based case study are presented by three demonstration cases focusing on manufacturing sector i.e. elevator, refrigerator and welding. Based on these cases result, we conclude that this is the first step in the right direction to use the ABC method to identify the suitable impact category sets for conducting LCA studies. The three simple questions that transfer selection criteria, i.e. robustness, relevance, effectiveness, practicality and clear and easy to measure, are found operational and appropriate
"Beat" patterns for the odd-even staggering in octupole bands from a quadrupole-octupole Hamiltonian
We propose a collective Hamiltonian which incorporates the standard
quadrupole terms, octupole terms classified according to the irreducible
representations of the octahedron group, a quadrupole-octupole interaction, as
well as a term for the bandhead energy linear in K (the projection of angular
momentum on the body-fixed z-axis). The energy is subsequently minimized with
respect to K for each given value of the angular momentum I, resulting in K
values increasing with I within each band, even in the case in which K is
restricted to a set of microscopically plausible values. We demonstrate that
this Hamiltonian is able to reproduce a variety of ``beat'' patterns observed
recently for the odd-even staggering in octupole bands of light actinides.Comment: LaTeX, 20 pages plus 12 figures given in separate .ps file
Mass Measurements of Neutron-Deficient Yb Isotopes and Nuclear Structure at the Extreme Proton-Rich Side of the N=82 Shell
International audienceHigh-accuracy mass measurements of neutron-deficient Yb isotopes have been performed at TRIUMF using TITANâs multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). For the first time, an MR-TOF-MS was used on line simultaneously as an isobar separator and as a mass spectrometer, extending the measurements to two isotopes further away from stability than otherwise possible. The ground state masses of Yb150,153 and the excitation energy of Ybm151 were measured for the first time. As a result, the persistence of the N=82 shell with almost unmodified shell gap energies is established up to the proton drip line. Furthermore, the puzzling systematics of the h11/2-excited isomeric states of the N=81 isotones are unraveled using state-of-the-art mean field calculation
Effects of the shape and Coriolis interaction in nuclear electromagnetic properties
We study the manifestation of collective vibrations and rotations coupled to single-particle motion in odd-mass nuclei with the presence of axial quadrupole-octupole deformations. Our model incorporates K-mixing effects stemming from the Coriolis interaction between the odd nucleon and the even-even core and thus takes into account the probabilities for otherwise forbidden due to the axial symmetry electromagnetic transitions between excited states built on different intrinsic configurations. We demonstrate these effects in the quasi-parity-doublet spectrum of the nucleus 221Fr in which a strong Coriolis interaction manifests. The model successfully describes the available intra- and interband E1, E2 and M1 transition rates giving an insight into the mechanism which allows the K-suppressed transitions in axially symmetric nuclei
Kommunikation von Umweltproduktinformationen: : Charakterisierung und Harmonisierung von Umweltzeichen
Environmental labels and declarations (or ecolabels) are instruments to communicate the environmental performance of products. The relevance of environmental communication has been highlighted in Europe as far back in the 2000s when the Integrated Product Policy has been settled. Nowadays, environmental labelling is among the policy tools supported by the European Commission (EC) in the improvement of sustainable production and consumption practices. However, ecolabels around the world have developed in many varieties and forms, due to the different communication purposes, target groups and aims they have. The ecolabels existing on the market barely can fit under any existing classification, including the one from the International Organization for Standardization (ISO). ISO manages the 14020-suite of standards designated to provide a framework for ecolabels development. The current ISO classification consists of three types: Type I ecolabels, Type II self-declared claims and Type III environmental product declarations.
The lack of operational classification and systematic approach for characterization of ecolabels is confusing for many users, as well as hinders the research work towards the improvement of their reliability and credibility. In this regard, credible ecolabels are considered those that are based on transparent operation and on scientifically-sound methodology for criteria development and assessment. A method worth exploring in ecolabelling is Life Cycle Assessment (LCA). Already proven and popular in business-to-business (B2B) setting (e.g., in Type III declarations), it is still criticised and not fully explored whether it is applicable in business-to-consumer (B2C) communication.
The objective of this work is to enhance the communication of environmental product information through improved characterization and harmonization of ecolabels. Two research questions are defined and answered to meet this objective, depicting two focus areas of the thesis: firstly, the area of characterization and classification of ecolabels and secondly, the application of LCA for harmonization in ecolabelling. This thesis is based on four peer-reviewed journal publications.
Improvements in the characterization of ecolabels are achieved by the development of a characterization scheme. It is a result of the investigation of a sample of 45 ecolabels and a literature review of existing publications on ecolabel classification and characterization. Based on the gained information, gaps of the ISO classification are highlighted. The application and performance of the scheme is further tested in a case study by characterizing the Cradle to Cradle Certifiedâą Products Program (C2C Certified for short) as a tool for external environmental communication.
Due to the formerly missing operational way to characterize ecolabels, some questions related to their overall harmonization and particularly to the application of LCA in ecolabels were still open. Thus, the work further focuses on LCA-based ecolabels (such as Type III declarations) and the existing approaches for harmonization of product category rules (PCR). By a desktop research, Type III-like programmes are identified, classified, and evaluated. Trends in their development along the years are observed. Regarding the overview of existing harmonization attempts, 16 initiatives categorized as guidelines, standards and technical specifications, collaborative platforms and other activities related to mutual recognition between parties are examined.
Focus is given on the Guidelines for Product Category Rule Development (GPCRD) and the ECâs Product Environmental Footprint initiative (PEF). A road test to align a draft PCR with the requirements of the GPCRD is conducted to evaluate the ability of the Guidelines to facilitate this process in a consistent manner. PEF is analysed from the perspective of an LCA-based instrument for environmental communication. It is compared with a typical Type I ecolabel â the European Ecolabel (EUF) â by conducting three case studies on detergents, paints, and t-shirts to show the interfaces between the two approaches. With the information obtained by the reciprocal analysis, three different perspectives for mutual integration and co-existence are examined.
The first version of the ecolabel characterization scheme contains 18 attributes, classified in four groups. Each attribute comprises two to five options to select among. For example, the attribute âEnd-user focusâ consists of three options: âB2Câ, âB2Bâ or âbothâ. The characterization of the ecolabels from the sample by employing the scheme shows that ecolabels apply different awarding formats and criteria in combinations and forms that are not recognized and described by ISO. Only around 40% of the ecolabels from the sample can be assigned to Type I and Type III. None of them declares to be Type II. As a result, a list of recommendations for improvement to ISO on seven different topics is derived. As an outcome of the case study on C2C Certified, an upgraded ecolabel characterization scheme is issued, consisting of five groups with 22 refined attributes. Proposals for improvement of C2C Certified as a communication tool are also determined.
As regards the harmonization of ecolabels and LCA application in ecolabelling, 48 Type-III-like programmes are listed. The results reveal that e.g., 56% of them operate in Europe, against 28% in North America. The majority cover the building and construction sector. The practical test of GPCRD concludes that the PCR alignment process is an attainable task and that GPCRD is a good complementary tool for Type III operators to strengthen their programme instructions. Several aspects for improvement and necessary common agreements between operators are listed to assure consistent PCR alignment.
As regards the comparison of PEF with EUF, few similarities and many divergences between the two approaches are noted. PEF is a relative approach and provides information on the potential life cycle environmental impacts, whereas the Type I ecolabel criteria are issue-specific and do not necessarily cover the complete life cycle of the product. Further, three perspectives are examined: PEF, EUF and Joint. The first two explore scenarios for mutual integration and co-existence between PEF and EUF. The joint perspective proposes a concept for an LCA-based hybrid ecolabel, building upon the synergies between a classic Type I and a Type III. The Type IV ecolabel, as called, allows for an overall harmonized and improved communication both on B2B and B2C level.
This thesis contributes to the scientific work on the enhancement of ecolabels characterization and harmonization. Its significance and actuality are justified by the current developments in standardization of ecolabels and communication of environmental information on both international and European level. The developed ecolabel characterization scheme is applicable for variety of cases and users; it is also considered as a foundation for improved ecolabels classification. As regards harmonization, the proposed Type IV hybrid ecolabel is an example of an action for reducing the proliferation of ecolabels.Umweltkennzeichnungen und -deklarationen (oder Umweltzeichen) sind Instrumente zur Kommunikation der Umweltleistung von Produkten. Die Bedeutung der Umweltkommunikation wurde in Europa bereits in den 2000er Jahren hervorgehoben, als die integrierte Produktpolitik festgelegt wurde. Heutzutage gehört die Umweltkennzeichnung zu den von der EuropĂ€ischen Kommission (EK) unterstĂŒtzten politischen Instrumenten zur Verbesserung nachhaltiger Produktions- und Verbrauchspraktiken. Aufgrund der unterschiedlichen Kommunikationszwecke, Zielgruppen und Ziele haben sich Umweltzeichen jedoch weltweit in vielen Varianten und Formen entwickelt. Die auf dem Markt existierenden Umweltzeichen passen kaum unter eine bestehende Klassifikation, auch nicht unter die der Internationalen Organisation fĂŒr Normung (ISO). Die ISO verwaltet die 14020-Normenreihe, die einen Rahmen fĂŒr die Entwicklung von Umweltzeichen bieten soll. Die aktuelle ISO-Klassifikation besteht aus drei Typen: Umweltzeichen vom Typ I, selbsterklĂ€rende Angaben vom Typ II und Umweltproduktdeklarationen vom Typ III.
Das Fehlen einer operationellen Klassifizierung und eines systematischen Ansatzes zur Charakterisierung von Umweltzeichen ist fĂŒr viele Benutzer verwirrend und behindert die Forschungsarbeit zur Verbesserung ihrer ZuverlĂ€ssigkeit und GlaubwĂŒrdigkeit. Als glaubwĂŒrdig gelten in diesem Zusammenhang Umweltzeichen, die auf einer transparenten Arbeitsweise und einer wissenschaftlich fundierten Methodik zur Entwicklung und Bewertung von Kriterien beruhen. Eine Methode, die es wert ist, bei der Vergabe von Umweltzeichen erforscht zu werden, ist die Ăkobilanz (LCA). Sie hat sich im Business-to-Business-Bereich (B2B) bereits bewĂ€hrt und ist beliebt (z.B. bei ErklĂ€rungen vom Typ III), wird aber immer noch kritisiert und nicht vollstĂ€ndig untersucht, ob sie in der Business-to-Consumer-Kommunikation (B2C) anwendbar ist.
Das Ziel dieser Arbeit ist es, die Kommunikation von ökologischen Produktinformationen durch eine verbesserte Charakterisierung und Harmonisierung von Umweltzeichen zu verbessern. Um dieses Ziel zu erreichen, werden zwei Forschungsfragen definiert und beantwortet, die zwei Schwerpunktbereiche der Arbeit darstellen: erstens den Bereich der Charakterisierung und Klassifizierung von Umweltzeichen und zweitens die Anwendung von Ăkobilanzen zur Harmonisierung der Umweltzeichen. Diese Arbeit basiert auf vier begutachteten Zeitschriftenveröffentlichungen.
Verbesserungen bei der Charakterisierung von Umweltzeichen werden durch die Entwicklung eines Charakterisierungsschemas erreicht. Es ist das Ergebnis der Untersuchung einer Stichprobe von 45 Umweltzeichen und einer LiteraturĂŒbersicht ĂŒber bestehende Publikationen zur Klassifizierung und Charakterisierung von Umweltzeichen. Auf der Grundlage der gewonnenen Informationen werden LĂŒcken in der ISO-Klassifizierung aufgezeigt. Die Anwendung und Leistung des Schemas wird in einer Fallstudie weiter getestet, indem das Cradle to Cradle Certifiedâą Products Program (kurz C2C Certified) als Werkzeug fĂŒr die externe Umweltkommunikation charakterisiert wird.
Aufgrund der bisher fehlenden operativen Möglichkeit zur Charakterisierung von Umweltzeichen waren einige Fragen bezĂŒglich ihrer allgemeinen Harmonisierung und insbesondere der Anwendung von Ăkobilanzen bei Umweltzeichen noch offen. Daher konzentriert sich die Arbeit weiter auf LCA-basierte Umweltzeichen (wie z.B. Typ III Deklarationen) und die bestehenden AnsĂ€tze zur Harmonisierung der Produktkategorieregeln (PĐR). Durch eine Desktop-Recherche werden Typ-III-Ă€hnliche Programme identifiziert, klassifiziert und bewertet. Es werden Trends in ihrer Entwicklung ĂŒber die Jahre hinweg beobachtet. Im Hinblick auf den Ăberblick ĂŒber die bestehenden Harmonisierungsversuche werden 16 Initiativen untersucht, die in Richtlinien, Normen und technische Spezifikationen, kollaborative Plattformen und andere AktivitĂ€ten im Zusammenhang mit der gegenseitigen Anerkennung zwischen den Parteien kategorisiert sind.
Der Schwerpunkt liegt auf den Richtlinien fĂŒr die Entwicklung von Produktkategorieregeln (GPCRD) und der Product Environmental Footprint Initiative (PEF) der EG. Es wird ein Test durchgefĂŒhrt, um einen PĐR-Entwurf mit den Anforderungen der GPCRD in Einklang zu bringen, um die FĂ€higkeit der Richtlinien zu bewerten, diesen Prozess auf konsistente Weise zu erleichtern. Die PEF wird aus der Perspektive eines LCA-basierten Instruments fĂŒr die Umweltkommunikation analysiert. Sie wird mit einem typischen Typ-I-Umweltzeichen - dem EuropĂ€ischen Umweltzeichen (EUF) - verglichen, indem drei Fallstudien zu Waschmitteln, Farben und T-Shirts durchgefĂŒhrt werden, um die Schnittstellen zwischen den beiden AnsĂ€tzen aufzuzeigen. Mit den durch die gegenseitige Analyse gewonnenen Informationen werden drei verschiedene Perspektiven fĂŒr die gegenseitige Integration und Koexistenz untersucht.
Die erste Version des Schemas zur Charakterisierung des Umweltzeichens enthĂ€lt 18 Attribute, die in vier Gruppen eingeteilt sind. Jedes Attribut umfasst zwei bis fĂŒnf Optionen zur Auswahl. Das Attribut "Endbenutzer-Fokus" beispielsweise besteht aus drei Optionen: "B2C", "B2B" oder "beide". Die Charakterisierung der Umweltzeichen aus der Stichprobe anhand des Schemas zeigt, dass die Umweltzeichen unterschiedliche Vergabeformate und -kriterien in Kombinationen und Formen anwenden, die von der ISO nicht anerkannt und beschrieben werden. Nur etwa 40% der Umweltzeichen aus der Stichprobe können dem Typ I und Typ III zugeordnet werden. Keines von ihnen erklĂ€rt sich als Typ II. Als Ergebnis wird eine Liste von Empfehlungen zur Verbesserung der ISO zu sieben verschiedenen Themen abgeleitet. Als Ergebnis der Fallstudie zu C2C Certified wird ein verbessertes Schema zur Charakterisierung des Umweltzeichens herausgegeben, das aus fĂŒnf Gruppen mit 22 verfeinerten Attributen besteht. Es werden auch VerbesserungsvorschlĂ€ge fĂŒr die C2C-Zertifizierung als Kommunikationsinstrument ermittelt.
Hinsichtlich der Harmonisierung von Umweltzeichen und der Anwendung von Ăkobilanzen bei der Vergabe von Umweltzeichen werden 48 Typ-III-Ă€hnliche Programme aufgefĂŒhrt. Die Ergebnisse zeigen, dass z.B. 56% von ihnen in Europa tĂ€tig sind, gegenĂŒber 28% in Nordamerika. Die Mehrheit deckt den Bau- und Konstruktionssektor ab. Der Praxistest des GPCRD kommt zu dem Schluss, dass der PCR-Abgleichprozess eine erreichbare Aufgabe ist und dass das GPCRD ein gutes ergĂ€nzendes Instrument fĂŒr Betreiber von Typ-III-Programmen ist, um ihre Programmanweisungen zu verstĂ€rken. Mehrere verbesserungswĂŒrdige Aspekte und notwendige gemeinsame Vereinbarungen zwischen den Betreibern werden aufgelistet, um eine konsistente PCR-Ausrichtung zu gewĂ€hrleisten.
Was den Vergleich von PEF und EUF betrifft, so sind wenige Ăhnlichkeiten und viele Abweichungen zwischen den beiden AnsĂ€tzen festzustellen. PEF ist ein relativer Ansatz und liefert Informationen ĂŒber die potenziellen Umweltauswirkungen ĂŒber den gesamten Lebenszyklus, wĂ€hrend die Kriterien fĂŒr das Umweltzeichen vom Typ I themenspezifisch sind und nicht unbedingt den gesamten Lebenszyklus des Produkts abdecken. Ferner werden drei Perspektiven untersucht: PEF, EUF und Joint. Die ersten beiden untersuchen Szenarien fĂŒr die gegenseitige Integration und Koexistenz von PEF und EUF. Die gemeinsame Perspektive schlĂ€gt ein Konzept fĂŒr ein LCA-basiertes hybrides Umweltzeichen vor, das auf den Synergien zwischen einem klassischen Typ I und einem Typ III aufbaut. Das Typ IV-Umweltzeichen, wie es genannt wird, ermöglicht eine insgesamt harmonisierte und verbesserte Kommunikation sowohl auf B2B- als auch auf B2C-Ebene.
Diese Arbeit leistet einen Beitrag zur wissenschaftlichen Arbeit ĂŒber die Verbesserung der Charakterisierung und Harmonisierung von Umweltzeichen. Ihre Bedeutung und AktualitĂ€t wird durch die aktuellen Entwicklungen bei der Standardisierung von Umweltzeichen und der Kommunikation von Umweltinformationen auf internationaler und europĂ€ischer Ebene begrĂŒndet. Das entwickelte Schema zur Charakterisierung von Umweltzeichen ist fĂŒr eine Vielzahl von FĂ€llen und Anwendern anwendbar; es wird auch als Grundlage fĂŒr eine verbesserte Klassifizierung von Umweltzeichen angesehen. Was die Harmonisierung betrifft, so ist das vorgeschlagene hybride Umweltzeichen vom Typ IV ein Beispiel fĂŒr eine MaĂnahme zur Verringerung der Verbreitung von Umweltzeichen
Nuclear coherent population transfer to the Th isomer using x-ray pulses
Population of the 8 eV Th isomer via the second nuclear excited
state at 29.19 keV by means of coherent x-ray pulses is investigated
theoretically. We focus on two nuclear coherent population transfer schemes
using partially overlapping x-ray pulses known from quantum optics: stimulated
Raman adiabatic passage (STIRAP), and successive pulses. Numerical
results are presented for three possible experimental setups. Our results
identify the Gamma Factory as the most promising scenario, where two
ultraviolet pulses combined with relativistically accelerated ions deliver the
required intensities for efficient isomer population. Our simulations require
knowledge of the in-band and cross-band nuclear transition probabilities. We
give theoretically predicted values for the latter and discuss them in the
context of recent experiments.Comment: 16 pages, 5 figures, 7 table