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Design and characterization of geopolymer foams reinforced with Miscanthus x giganteus fibers
(2024)
This paper presents the effects of different amounts of fibers and foaming agent, as well as different fiber sizes, on the mechanical and thermal properties of fly ash-based geopolymer foams reinforced with Miscanthus x giganteus fibers. The mechanical properties of the geopolymer foams were measured through compressive strength, and their thermal properties were characterized by thermal conductivity and X-ray micro-computed tomography. Furthermore, design of experiment (DoE) were used to optimize the thermal conductivity and compressive strength of Miscanthus x giganteus reinforced geopolymer foams. In addition, the microstructure was studied using X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR). Mixtures with a low thermal conductivity of 0.056 W (m K)−1 and a porosity of 79 vol% achieved a compressive strength of only 0.02 MPa. In comparison, mixtures with a thermal conductivity of 0.087 W (m K)−1 and a porosity of 58 vol% achieved a compressive strength of 0.45 MPa.
Trade of wild-caught animals is illegal for many taxa and in many countries. Common regulatory procedures involve documentation and marking techniques. However, these procedures are subject to fraud and thus should be complemented by routine genetic testing in order to authenticate the captive-bred origin of animals intended for trade. A suitable class of genetic markers are SNPSTRs that combine a short tandem repeat (STR) and single nucleotide polymorphisms (SNPs) within one amplicon. This combined marker type can be used for genetic identification and for parentage analyses and in addition, provides insight into haplotype history. As a proof of principle, this study establishes a set of 20 SNPSTR markers for Athene noctua, one of the most trafficked owls in CITES Appendix II. These markers can be coamplified in a single multiplex reaction. Based on population data, the percentage of observed and expected heterozygosities of the markers ranged from 0.400 to 1.000 and 0.545 to 0.850, respectively. A combined probability of identity of 5.3*10-23 was achieved with the whole set, and combined parentage exclusion probabilities reached over 99.99%, even if the genotype of one parent was missing. A direct comparison of an owl family and an unrelated owl demonstrated the applicability of the SNPSTR set in parentage testing. The established SNPSTR set thus proved to be highly useful for identifying individuals and analysing parentage to determine wild or captive origin. We propose to implement SNPSTR-based routine certification in wildlife trade as a way to reveal animal laundering and misdeclaration of wild-caught animals.
The lattice Boltzmann method (LBM) stands apart from conventional macroscopic approaches due to its low numerical dissipation and reduced computational cost, attributed to a simple streaming and local collision step. While this property makes the method particularly attractive for applications such as direct noise computation, it also renders the method highly susceptible to instabilities. A vast body of literature exists on stability-enhancing techniques, which can be categorized into selective filtering, regularized LBM, and multi-relaxation time (MRT) models. Although each technique bolsters stability by adding numerical dissipation, they act on different modes. Consequently, there is not a universal scheme optimally suited for a wide range of different flows. The reason for this lies in the static nature of these methods; they cannot adapt to local or global flow features. Still, adaptive filtering using a shear sensor constitutes an exception to this. For this reason, we developed a novel collision operator that uses space- and time-variant collision rates associated with the bulk viscosity. These rates are optimized by a physically informed neural net. In this study, the training data consists of a time series of different instances of a 2D barotropic vortex solution, obtained from a high-order Navier–Stokes solver that embodies desirable numerical features. For this specific text case our results demonstrate that the relaxation times adapt to the local flow and show a dependence on the velocity field. Furthermore, the novel collision operator demonstrates a better stability-to-precision ratio and outperforms conventional techniques that use an empirical constant for the bulk viscosity.
This article deals with the under-researched phenomenon of rural health entrepreneurship and its major characteristics. The purpose of this study is to explicate the process of providing health services in rural areas of a developing country and their relation to SDGs. The paper is based on six semi-structured interviews conducted with Serbian health entrepreneurs in rural areas (two private practices, two policlinics, and two dental practices), a review of laws and strategies relevant to the field, and three sessions of discussions with eight experts (four authors and four additional experts). The research methodology follows an empirical, mixed-method case study research procedure. The results are presented in relation to the aspects of frugality, family orientation, and sustainability-oriented innovation. The timeline of the six case studies demonstrates the increasing importance of health entrepreneurs in rural areas due to the aging population and, therefore, increased needs for quality healthcare in these areas. The financing instruments have also become more formal and substantial in recent years, enabling the growth of healthcare businesses in rural areas. However, a major obstacle to further sustainable development remains the non-refundability of services before the state-owned, obligatory health fund, creating major social inequalities, especially in rural areas.
The Peren Theorem
(2024)
The Peren-Clement Index
(2024)
Network Analysis Method
(2024)
Dynamic Programming
(2024)
Heuristic Methods
(2024)
Sequencing Problems
(2024)
Queueing Theory
(2024)
Linear Optimization
(2024)
The Decision Tree Procedure
(2024)
In addition to the long-term goal of mitigating climate change, the current geopolitical upheavals heighten the urgency to transform Europe's energy system. This involves expanding renewable energies while managing intermittent electricity generation. Hydrogen is a promising solution to balance generation and demand, simultaneously decarbonizing complex applications. To model the energy system's transformation, the project TransHyDE-Sys, funded by the German Federal Ministry of Education and Research, takes an integrated approach beyond traditional energy system analysis, incorporating a diverse range of more detailed methods and tools. Herein, TransHyDE-Sys is situated within the recent policy discussion. It addresses the requirements for energy system modeling to gain insights into transforming the European hydrogen and energy infrastructure. It identifies knowledge gaps in the existing literature on hydrogen infrastructure-oriented energy system modeling and presents the research approach of TransHyDE-Sys. TransHyDE-Sys analyzes the development of hydrogen and energy infrastructures from “the system” and “the stakeholder” perspectives. The integrated modeling landscape captures temporal and spatial interactions among hydrogen, electricity, and natural gas infrastructure, providing comprehensive insights for systemic infrastructure planning. This allows a more accurate representation of the energy system's dynamics and aids in decision-making for achieving sustainable and efficient hydrogen network development integration.
Chain models as a tool to quantify the relation between soil, crop quality and human exposure
(2008)
„from stable to table“
(2008)
Chloritesare found in igneous rocks, and more commonly
in sediments and low grade metamorphic rocks (BrinJiey &
Brown 1980). Because chlorites are less stable than most of
the other clay minerals when placed into an acidic
environment (Barnhisel & Bertsch 1989), they play
significant roles in the solution chemistry and may be an
important source of magnesium and micronutrients in soils
(Ross 1975). The objective of the present study was to
compare the weathering behavior of different chlorites in
different chemical environments.
Introduction: The paper analyses – basing itself on reports and other documents created by different parts of the International Labour Organisation (ILO) – the process which led to the adoption of Social Protection Floor Recommendation No. 202 and the shift in focus of social policy advice towards basic protection and to the Global South countries. We look at the actions of different actors which shape the standard setting and policy stand of the organisation. Objective: To provide a comprehensive analysis of the historical trajectory of ILO social security standards, examining the evolution of principles, conventions, and the global dynamics that have shaped the organization's approach to social protection over time. Materials and methods: The methods include examining ILO documents, relevant subject literature, and the author's participant observations from over twenty-years of service in the ILO's Social Security Department, aiming to provide insights into the decision-making processes within the organization. Conclusion: We conclude that change was brought by: 1) shift in the membership of the ILO and of its decision-making bodies towards the increased presence and powers of representatives from countries of the Global South, 2) the shift in the global development community policy priorities towards poverty reduction, 3) emergence of experimental social assistance schemes in Global South countries, with designs often ignoring principles embedded in the ILO standards. The Social Protection Floor Recommendation complements previous standards in response to the challenges of widespread poverty and informality and spreading atypical forms of employment. It provides two directions of policy responses: 1) formalizing informal employment relationships and 2) expanding universal or targeted rights-based social assistance schemes. Assistance provided by ILO to member states focuses now more on building the non-contributory schemes and on identifying the fiscal space necessary to close the coverage gaps. Nowadays, the ILO must collaborate more than before with other development partners and the main challenge is to build among them awareness and acceptance of the principles of the ILO social security standards.
There are several recent works which had proposed an automatic computer-aided diagnosis (CAD) deep learning (DL) model to diagnose coronavirus disease 2019 (COVID-19) using chest x-ray images (CXR) to propose a high-accuracy CAD method to detect COVID-19 automatically. In this study, seven different models including Convolutional Neural Network (CNN) models such as VGG-16 and vision transformer (ViT) models, are proposed. The different proposed models are trained with a three-class balanced dataset consisting of 3,000 CXR images consisting of 1,000 CXR images for each class of COVID-19, Normal, and Lung-Opacity. A publicly available dataset to train and test the models is used from Kaggle-COVID-19-Radiography-Dataset. From the experiments, the accuracy of the VGG16 model is 93.44% and ViT's is 92.33%. Besides, the binary classification between two classes of COVID-19 and Normal CXR with a limited number of just 100 images for each class, using a transfer learning technique, with a validation accuracy of 97.5% is proposed.
The transport of carbon dioxide through pipelines is one of the important components of Carbon dioxide Capture and Storage (CCS) systems that are currently being developed. If high flow rates are desired a transportation in the liquid or supercritical phase is to be preferred. For technical reasons, the transport must stay in that phase, without transitioning to the gaseous state. In this paper, a numerical simulation of the stationary process of carbon dioxide transport with impurities and phase transitions is considered. We use the Homogeneous Equilibrium Model (HEM) and the GERG-2008 thermodynamic equation of state to describe the transport parameters. The algorithms used allow to solve scenarios of carbon dioxide transport in the liquid or supercritical phase, with the detection of approaching the phase transition region. Convergence of the solution algorithms is analyzed in connection with fast and abrupt changes of the equation of state and the enthalpy function in the region of phase transitions.
This work proposes a novel approach for probabilistic end-to-end all-sky imager-based nowcasting with horizons of up to 30 min using an ImageNet pre-trained deep neural network. The method involves a two-stage approach. First, a backbone model is trained to estimate the irradiance from all-sky imager (ASI) images. The model is then extended and retrained on image and parameter sequences for forecasting. An open access data set is used for training and evaluation. We investigated the impact of simultaneously considering global horizontal (GHI), direct normal (DNI), and diffuse horizontal irradiance (DHI) on training time and forecast performance as well as the effect of adding parameters describing the irradiance variability proposed in the literature. The backbone model estimates current GHI with an RMSE and MAE of 58.06 and 29.33 W m−2, respectively. When extended for forecasting, the model achieves an overall positive skill score reaching 18.6 % compared to a smart persistence forecast. Minor modifications to the deterministic backbone and forecasting models enables the architecture to output an asymmetrical probability distribution and reduces training time while leading to similar errors for the backbone models. Investigating the impact of variability parameters shows that they reduce training time but have no significant impact on the GHI forecasting performance for both deterministic and probabilistic forecasting while simultaneously forecasting GHI, DNI, and DHI reduces the forecast performance.
Integrating physical simulation data into data ecosystems challenges the compatibility and interoperability of data management tools. Semantic web technologies and relational databases mostly use other data types, such as measurement or manufacturing design data. Standardizing simulation data storage and harmonizing the data structures with other domains is still a challenge, as current standards such as the ISO standard STEP (ISO 10303 ”Standard for the Exchange of Product model data”) fail to bridge the gap between design and simulation data. This challenge requires new methods, such as ontologies, to rethink simulation results integration. This research describes a new software architecture and application methodology based on the industrial standard ”Virtual Material Modelling in Manufacturing” (VMAP). The architecture integrates large quantities of structured simulation data and their analyses into a semantic data structure. It is capable of providing data permeability from the global digital twin level to the detailed numerical values of data entries and even new key indicators in a three-step approach: It represents a file as an instance in a knowledge graph, queries the file’s metadata, and finds a semantically represented process that enables new metadata to be created and instantiated.
This paper presents the b-it-bots RoboCup@Work team and its current hardware and functional architecture for the KUKA youBot robot. We describe the underlying software framework and the developed capabilities required for operating in industrial environments including features such as reliable and precise navigation, flexible manipulation, robust object recognition and task planning. New developments include an approach to grasp vertical objects, placement of objects by considering the empty space on a workstation, and the process of porting our code to ROS2.
The Global Compact for Safe, Orderly and Regular Migration defines Global Skill Partnerships (GSP) as an innovative means of strengthen skills development among origin countries and countries of destination in mutually beneficial manner. However, GSPs are very limited in number and scope, and empirical analyses of them are, to date, relatively rare. This study helps fill this gap in data by presenting and examining existing GSPs or GSP-like approaches (e.g., transnational training partnerships). The aim of the study is to take stock of the various conceptual discourses on and practical experience with transnational skill partnerships. Using Kosovo as a case study, the study details the structure of such partnerships and the processes they entail. It documents the experience of those involved and catalogues the factors contributing to success. On this basis, the authors propose a means of categorizing the various practices that will help structure the empirical diversity of such approaches and render them conceptually feasible: Transnational Skills and Mobility Partnerships (TSMP).
This paper presents the preliminary results of the Socialist Republic of Vietnam country case study conducted as part of the research project Sustainable Labour Migration implemented by the University of Applied Science Bonn-Rhein-Sieg. The project focuses on stakeholder perspectives on countries of origin benefits and the sustainability of different transnational skill partnership schemes. Existing and ongoing small-scale initiatives indicate that opportunities exist for all three types of labour mobility pathways, from recruiting youth for apprenticeships and subsequent skilled work to recruitment and recognition of skilled 'professionals' certificates for direct work contracts to initial vocational education and training programs in a dual-track approach. While the latter has the highest potential to be more beneficial than other approaches, pursuing and supporting the scaling up of all three pathways in parallel will have additional, mutually reinforcing and supporting effects. The potential for benefits over and above those already realised by existing skill partnerships appears high, especially considering the favourable framework conditions specific to the long-standing German-Vietnamese relationship. If the potential of well-managed skill partnerships was realised, such sustainable models of skilled labour migration could serve as a unique selling point in the international competition for skilled labour.
What does ‘desirable’ or ‘sustainable’ mean in the context of labour migration? And what should programmes geared towards making migration more compatible with development look like? These questions provided the starting point for the ‘Sustainable Labour Migration’ research project implemented by Hochschule Bonn-Rhein-Sieg University of Applied Sciences between December 2020 and August 2022. The project looked at how sustainability in different transnational skills partnership schemes was perceived by different stakeholders in three countries chosen as case studies: Georgia, Kosovo and Vietnam. Embracing the notion of a ‘triple win’, many transnational skills partnership schemes aim to deliver benefits for their main stakeholder groups. As well as reflecting critically on this triple-win narrative, this paper also argues for a more nuanced approach in order to grasp the complexity of skilled labour migration. The paper introduces one such approach, namely the sustainable labour migration framework, and highlights the key elements of the research project. It details the methodology used in the study (systematic literature review – employer survey – semi-structured, in-depth interviews – focus group interviews) and explores the perception of sustainability in skilled labour migration with a focus on the cost/benefit ratio, the relationship between vocational education and training and labour migration, and the various arrangements for the partnerships employed in the schemes. In introducing the key findings from the three countries selected for the case studies, the paper highlights that the perception of sustainability is not underpinned by a comprehensive understanding of the term amongst most stakeholders. Within all the schemes, however, some stakeholders identified elements which make a positive contribution to development in the respective countries of origin and thus identify elements of sustainable labour migration with room for improvement in multiple areas. The paper concludes with a presentation of overall policy recommendations: The ongoing reform of Germany’s labour migration policy should be accompanied by more development-oriented activities. As part of this, the German Federal Ministry for Economic Cooperation and Development (BMZ) should stand up more forcefully for the needs of migrants and potential partner countries in order to reduce existing inequalities
In intensively used agricultural landscapes, path margins are one of the few refuges and nurseries for wildlife. They provide e. g. food sources and overwintering opportunities for many insects, serve as migration corridors for animals, protect soil from erosion, increase its water-holding capacity, and increase soil organic carbon, contributing thus directly to biodiversity conservation and climate change mitigation. Path margins are often municipally owned but used and managed by agriculture. For a path margin to be functional, certain conditions must be fulfilled, such as the width, the botanical composition, and how it is managed through the seasons. Therefore, it must be managed under specific requirements. A multifunctional path margin can be achieved only through the commitment of all stakeholders (e.g., farmers, municipalities, conservationists, and civil society).
The art of nudging
(2023)
Do simple and subtle changes in the living and study environment improve the eating behaviour of students in an educational setting? This dissertation provides a not-so-simple answer to this simple question based on the outcomes of four studies that explore the effects and design of artwork nudges (specifically the artwork of Alberto Giacometti) on the eating behaviour of students by applying different research designs. Study 1 explores the effects of a Giacometti-like nudge (a more contemporary version of the original nudge) regarding the dietary behaviour of high school students in a controlled setting. Study 2 applies different artwork nudges within a virtual vignette setting to measure their effects on virtual meal choices made. Also, the degree to which individuals were aware of the nudge’s presence is included as an influential factor in nudge effectiveness. Study 3 assesses the susceptibility to nudges as measured with a questionnaire. Susceptibility to nudges is defined as nudgeability. Study 4 assesses the effects of the original Giacometti nudge in a real-world university cafeteria setting. Specifically, the immediate and sustained effects of the original Giacometti nudge on students’ meal purchases in the university cafeteria are considered. In addition, the role of awareness of the nudge’s presence as well as the acceptance of this specific nudge are discussed. The conclusion is drawn that the original Giacometti nudge should only be applied in an educational setting to improve healthy eating behaviour if the intended target groups and environment meet certain conditions. Artwork nudges in general should be applied only after rigorous testing of various types of different nudges and more research reflecting healthy eating in its entirety.