bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fiscal Federalism in Germany
Authors: Bury Yannick , Feld Lars P. 
Published: July 2023

AbstractFrom the year 2020 onwards, major constitutional changes have inverted former principles of German fiscal federalism and have led to further vertical fiscal imbalances. The latest reform of Germany’s fiscal federalism strengthens the federal level in general and the executive branches at the federal and state (Laender) tiers of government in particular at the expense of the Laender and their parliaments, respectively. In view of this development, this chapter provides an overview of the components of fiscal federalism in Germany. After providing a brief characterization of the country, we discuss the division of fiscal powers, the possibilities for the different levels of government to generate revenues, and the system of intergovernmental transfers. Besides describing the current situation, we discuss how the latest reform act has changed these dimensions of fiscal federalism since 2020.
South Africa
Authors: Mabugu Ramos Emmanuel , Rakabe Eddie M. 
Published: July 2023

AbstractThis chapter focuses on contemporary issues in South Africa’s evolving and unique system of quasi-federal governance. In what appears to be an unending and polymorphous federal reforms further complicated by the ongoing COVID-19 imposed fiscal pressures, the chapter explores the rationale and effectiveness of constitutional and fiscal institutions underpinning South Africa’s multi-level governance. Coming from a difficult apartheid past, the country was able to install a “compromised” intergovernmental relations system, constituted by the Constitution as three spheres of government that are distinctive, interrelated and interdependent. The system is supported by a myriad of enabling legislations and institutions to harness accountability and fiscal management as well as the intergovernmental transfers to facilitate delivery of basic services. Notwithstanding the legislative and institutional framework, the system is beset by a gamut of challenges as it evolves in search of an identity. Foremost among these challenges is the absence of political commitment and clear vision for decentralisation, which manifest (and often impinge) in the execution of concurrent, own and delegated expenditure responsibilities and more importantly the assignment of taxing powers across the three spheres of government. As the system continues to mature in search of optimal decentralisation, this chapter argues for a “clearer federalism vision” around which intergovernmental fiscal relations reforms could be anchored.
Constructing the Self Between Worlds
Authors: Kullberg Christina 
Published: July 2023

AbstractThis chapter shifts the attention toward another point of entanglement, namely the construction of the travelers’ self as a changing narrative category within the travel narratives. Drawing on recent research around the complex development of the notion of the self in the seventeenth century, the argument is that the self is unstable and multiple; it mediates between the space of reception (France) and the space described (the Islands). The self thus becomes a site where the effect of otherness can be traced: it becomes a narrative locus of unsettlement where the impact of early island society and its people is visible on several levels. The first section is devoted to the conditions governing travel writing in order to understand how the travelers used this strategically in their representations of the islands in terms of both distance and embodiment. The second section centers on Labat’s travelogue in order to analyze how that embodiment led to the construction of an experimental self influenced by the islands: the individual traveler’s experience becomes a way to think through the social body’s experience. The third section examines how the self negotiates encounters with others. By interrogating the figure of the commentary, it questions the construction of a discourse of ambivalence, bordering on sentimentality, with regard to enslaved peoples and enslavement as an institution. The last section looks closer at engagements with Indigenous peoples in terms of an anxiety of influence: the narratives configure that influence through style. The travelers, it claims, both underscore and distance themselves to uphold an intermediary position.
Review of Theories and a New Classification of Tortuosity Types
Authors: Holzer Lorenz , Marmet Philip , Fingerle Mathias , Wiegmann Andreas , Neumann Matthias , Schmidt Volker 
Published: July 2023

AbstractMany different definitions of tortuosity can be found in literature. In addition, also many different methodologies are nowadays available to measure or to calculate tortuosity. This leads to confusion and misunderstanding in scientific discussions of the topic. In this chapter, a thorough review of all relevant tortuosity types is presented. Thereby, the underlying concepts, definitions and associated theories are discussed in detail and for each tortuosity type separately. In total, more than 20 different tortuosity types are distinguished in this chapter. In order to avoid misinterpretation of scientific data and misunderstandings in scientific discussions, we introduce a new classification scheme for tortuosity, as well as a systematic nomenclature, which helps to address the inherent differences in a clear and efficient way. Basically, all relevant tortuosity types can be grouped into three main categories, which are (a) the indirect physics-based tortuosities, (b) the direct geometric tortuosities and (c) the mixed tortuosities. Significant differences among these tortuosity types are detected, when applying the different methods and concepts to the same material or microstructure. The present review of the involved tortuosity concepts shall serve as a basis for a better understanding of the inherent differences. The proposed classification and nomenclature shall contribute to more precise and unequivocal descriptions of tortuosity.
Towards a Quantitative Understanding of Microstructure-Property Relationships
Authors: Holzer Lorenz , Marmet Philip , Fingerle Mathias , Wiegmann Andreas , Neumann Matthias , Schmidt Volker 
Published: July 2023

Abstract100 years ago, the concept of tortuosity was introduced by Kozeny in order to express the limiting influence of the microstructure on porous media flow. It was also recognized that transport is hindered by other microstructure features such as pore volume fraction, narrow bottlenecks, and viscous drag at the pore surface. The ground-breaking work of Kozeny and Carman makes it possible to predict the macroscopic flow properties (i.e., permeability) based on the knowledge of the relevant microstructure characteristics. However, Kozeny and Carman did not have access to tomography and 3D image analysis techniques, as it is the case nowadays. So, their descriptions were developed by considering simplified models of porous media such as parallel tubes and sphere packings. This simplified setting clearly limits the prediction power of the Carman-Kozeny equations, especially for materials with complex microstructures. Since the ground-breaking work of Kozeny and Carman many attempts were undertaken to improve the prediction power of quantitative expressions that describe the relationship between microstructure characteristics (i.e., tortuosity τ, constrictivity β, porosity ε, hydraulic radius rh) and effective transport properties (i.e., conductivity σeff, diffusivity Deff, permeability к,). Due to the ongoing progress in tomography, 3D image-processing, stochastic geometry and numerical simulation, new possibilities arise for better descriptions of the relevant microstructure characteristics, which also leads to mathematical expressions with higher prediction power. In this chapter, the 100-years evolution of quantitative expressions describing the micro–macro relationships in porous media is carefully reviewed,—first, for the case of conduction and diffusion,—and second, for flow and permeability.The following expressions are the once with the highest prediction power:$$\sigma_{eff} \left( {or D_{eff} } \right) = \varepsilon^{1.15} \beta^{0.37} /\tau_{{dir_{geodesic} }}^{4.39} ,$$

σ

eff

o
r

D

eff

=

ε

1.15

β

0.37

/

τ

d
i

r

geodesic

4.39

,

for conduction and diffusion, and$$\kappa_{I} = 0.54\left( {\frac{\varepsilon }{{S_{V} }}} \right)^{2} \frac{{\varepsilon^{3.56} \beta^{0.78} }}{{\tau_{dir\_geodesic}^{1.67} }},$$

κ
I

=
0.54

ε

S
V

2

ε

3.56

β

0.78

τ

d
i
r
_
g
e
o
d
e
s
i
c

1.67

,

$$\kappa_{II} = \frac{{\left( {0.94r_{min} + 0.06r_{max} } \right)^{2} }}{8} \frac{{\varepsilon^{2.14} }}{{\tau_{dir\_geodesic}^{2.44} }},$$

κ

II

=

0.94

r

min

+
0.06

r

max

2

8

ε

2.14

τ

d
i
r
_
g
e
o
d
e
s
i
c

2.44

,

both, for permeability in porous media.
Summary and Conclusions
Authors: Holzer Lorenz , Marmet Philip , Fingerle Mathias , Wiegmann Andreas , Neumann Matthias , Schmidt Volker 
Published: July 2023

AbstractA short summary is provided for each chapter of the book, which includes a review of theories and a new classification of tortuosity types (chapter 2), a review of empirical data (tortuosity-porosity relationships) from literature (chapter 3), a review of image based methodologies, workflows, and calculation approaches for tortuosity (chapter 4), and a review of quantitative expressions for microstructure—property relationships considering transport in porous media (chapter 5). As a final conclusion, interpretations are given for the three main tortuosity categories: direct geometric, indirect physics-based and mixed tortuosities.
The Effect of Fishing Nets Aging on Metal Uptake
Authors: Lima Ana Teresa Macas , Bertelsen Ida Maria Gieysztor , Ottosen Lisbeth Mølgaard , James Neil A. 
Published: July 2023

AbstractFishing nets are mainly constituted of Polyethylene (PE), Polyamide, Polyethylene terephthalate (PET), Polypropylene (PP), and Nylon. While new, these plastics exhibit pristine mechanical performance but lose it as they age. But what about their metal adsorptive performance? Literature finds that plastics like PET and PVC accumulate Al, Cr, Mg, Fe, Co, Ni, Zn, Cd, and Pb, even when exposed to very low concentrations. This is mainly true for aged PVC (Kedzierski et al. Adsorption/desorption of Micropollutants. Mar Pollut Bull. 127:684–694, 2018). In this study, we look at the effect of age on the properties of fishing nets, including their capacity to adsorb metals. Because fishnets are in great part constituted by PE, we used standardized PE pellets as our reference. In calorimeter signaling, we observed that end-of-life fishing nets display a very different differential scanning calorimetry (DSC) pattern; both new and old fishing nets are very different from standardized PE polymer. Preliminary results show that Cr, Cu, Pb, and Se adsorption onto fishing nets occurs in the first 10 min to 6 h of exposure (24 h for Se). The maximum uptake was registered at 11 mg Cr kg‒1, 38 mg Cu kg‒1, 27 mg Pb kg‒1, and 15 mg Se kg‒1. All these concentrations refer to old end-of-life PE fishing nets, where new, unused PE fishing nets adsorb 2–20 times less (Old in this chapter refers to used fishing nets. The term is not attempting to attribute a particular life span/age to the nets). A comparison to different EU directives that regulate metal content in plastics for different end-uses shows that the old end-of-life PE fishing nets, after exposure to heavy metals, do not meet the regulations for hazardous waste. We believe that Greenlandic old waste fishing nets can be used to clean the wastewater, or metal-contaminated water, in Greenland and eventually, the rest of the world.
Quadruple Helix Relational Approach to Recycling Fishing Nets: Cluster Development in the Norwegian West Coast Region
Authors: Vaagen Hajnalka , Tippett Arron Wilde 
Published: July 2023

AbstractThe study presented in this chapter takes the quadruple helix relational perspective to develop a regional innovation cluster for fishing nets recycling and upcycling. A multi-method approach is proposed—triangulating cluster development approaches with the quadruple helix model of innovation and organisational network analysis—to explore clustering abilities by network structures that promote linkages for well-organised circular value chains, regional innovation processes, brokerage of innovative ideas and other cluster-related structures, and relational patterns.
The Role of Non-profit Organisations (NGOs) in Value Creation: Lessons from the Recycling of Fishing Gear in Norway
Authors: Glavee-Geo Richard , AI Ahmed Sardar Wasi Uddin , Tippett Arron Wilde , Grimstad Siv Marina Flø , Pasquine Mark 
Published: July 2023

AbstractValue chain collaboration and volunteering by non-governmental organisations (NGOs) are success factors that enhance fishing gear recycling. Using multiple cases of NGOs from the Norwegian value chain of recycled plastic fishing gear, we highlight the role of NGOs in fishing gear recycling through collaborative partnerships with small- and medium-sized enterprises (SMEs). The Blue Circular Economy (BCE) project provided us with the opportunity to understudy and highlight this contextually rich phenomenon. Our study shows that sustainable value creation can be achieved through marine plastics recycling, value chain collaboration, volunteering initiatives/operations, and local innovation system (LIS) leading to new process, service, and product development. The chapter provides increased understanding of the role of NGOs within the value chain. Value chain collaboration between SMEs and NGOs stimulates innovation in the local environment (LIS) and within the industry. Collaboration drives the innovation process and enhances recycling of marine plastics. Marine plastics with a focus on waste fishing gear recycling can lead to sustainable value creation. NGOs therefore occupy a key position in the value chain not only for advocacy, but also for value creation.
Symmetric Cryptography
Authors: Weissbaum François , Lugrin Thomas 
Published: July 2023

AbstractSymmetric encryption is the most common method to guarantee the confidentiality of a message or information. Encryption is a cryptographic process that makes it impossible for anyone who needs the decryption key to gain knowledge of plaintext. It is called symmetric when it uses the same key for encryption and decryption. The required key length for symmetric encryption must be at least 256 bits to guarantee sufficient protection against brute force attacks and the possible arrival of quantum computers. To conclude, well-established cryptographic libraries implementing standard algorithms should be preferred over homemade implementation.
Biometrics
Authors: Ding Sophia , Nunes Emilia , Bettendorff Pascal , Lin Weyde 
Published: July 2023

AbstractIn biometrics, physiological characteristics (e.g., fingerprints, facial features, voices) are measured to identify individuals. Since biometry does not share the same characteristics as other authentication techniques, such as passwords or PIN codes, it is widely used as a second-factor authentication. A fully integrated solution offers significant advantages as it aligns biometric hardware, key generation, validation, and storage with the cryptographic provider, providing a coherent control environment. As a result, designing and implementing secure biometric authentication methods requires highly specialized technical expertise and experience. In addition, as biometrics become prevalent and their integration with artificial intelligence systems increases, ethical and regulatory questions become more pressing.
Secure Positioning and Localization
Authors: Strohmeier Martin 
Published: July 2023

AbstractSecure positioning and localization refer to the use of technology to accurately determine the location of an object or person in a secure and trustworthy manner. It involves GPS, Bluetooth, Wi-Fi, and other wireless technologies to determine location. Several methods have been proposed to address this problem by securing the content of the signals cryptographically. Distance bounding and timed efficient stream loss-tolerant authentication are two leading examples. Furthermore, with autonomous vehicles becoming increasingly essential and utilized in all domains (land, water, air), secure and robust positioning and navigation capabilities will be crucial.
Email Security
Authors: Nunes Emilia 
Published: July 2023

AbstractEmails were not designed with cyber-attack protection in mind, making them an attractive target for cybercriminals. A primary attack vector is phishing, a type of social engineering in which a fraudulent message is sent to trick a person. however, email messages can be secured using cryptography. For example, end-to-end encryption could protect them in transit and at rest. In addition, transport Layer Security is used to protect emails in transit between email servers and clients. Nevertheless, emails may never be as secure as newly designed solutions with solid end-to-end encryption and robust architecture.
Secure Messaging
Authors: Nunes Emilia 
Published: July 2023

AbstractA message is defined as any piece of information that a person communicates to another individual or group. On the other hand, a secure messaging system protects and secures individuals’ and organizations’ communication infrastructure. End-to-end encryption uses encryption and decryption keys to ensure the privacy of messages and the authenticity of the sender and recipient. Technological advancements, such as cloud-based and blockchain-based platforms, drive growth in the secure messaging market. However, risks like phishing and cyberattacks remain persistent and are projected to continue targeting messages in the future.
Trends in Open Source Software for Data Protection and Encryption Technologies
Authors: Teijeiro Lucía Gómez , Maillart Thomas 
Published: July 2023

AbstractSoftware editors and practitioners have increasingly developed and used open-source software tools to implement their cybersecurity strategies. By its unique intellectual property regime, open-source software fosters transparency and sharing values, which have been recognized as important to finding and fixing vulnerabilities and quickly avoiding threats. By selecting 41 technologies related to the one presented in the book, we show that open-source software for cybersecurity is a rapidly growing complex ecosystem of 3456 GitHub repositories with 5000+ users. While some repositories are prominent, many have evolved under the radar, serving niche or emergent needs. Here, we provide the first account of trends in open-source software for cybersecurity and develop a non-parametric forecasting approach to provide an outlook of its development towards 2025.
Hash Functions
Authors: Wagner Urs , Lugrin Thomas 
Published: July 2023

AbstractHash functions are one-way functions that map arbitrary-length input to fixed-length output. Moreover, they have many cryptographic applications, such as integrity checks, password storage, and signatures. Cryptographic hash functions have some additional properties that can be formulated as hard problems: pre-image resistance, second pre-image resistance, and collision resistance. A significant technological development in this area is unlikely. Standardized hash functions are considered secure, and open-source implementations can be used at no cost. To conclude, the security properties required from hash functions depend on the intended purpose.
Zero-Knowledge Proof
Authors: Aad Imad 
Published: July 2023

AbstractZero-knowledge proofs are techniques to verify claims without revealing the information itself. In this process, a “prover” shares proof of their claim with a “verifier,” who then verifies the accuracy of the proof without learning any additional information. It does not prove things with certainty. Instead, the process is repeated as often as needed, eventually reaching near-certainty. Zero-knowledge proofs are still in their early days as open initiatives and standardization efforts involve industry, academia, and technical and non-technical specialist. There are different Zero-knowledge proof systems for different use cases, most of which are either being researched or open-source implementation.
Quantum Key Distribution
Authors: Rödiger Jasper 
Published: July 2023

AbstractA new class of computers, so-called quantum computers, will soon be able to crack common encryption algorithms. Quantum key distribution is a promising solution to stay secure in the age of the quantum computer, which is progressively getting industrialized in recent years. Worldwide, point-to-point quantum key distribution links are combined into larger and larger testbed networks, which approach more and more commercially usable networks. Topics like certification and standardization have become increasingly important for quantum key distribution.
Bioinspired Soft Actuator Based on Photothermal Expansion of Biodegradable Polymers
Authors: Cecchini Luca , Mariani Stefano , Pugno Nicola M. , Mazzolai Barbara 
Published: July 2023

AbstractThe combined effects of thermo-sensitive and photothermal materials present novel actuation strategies for wireless application and the use of sustainable energy sources, such as the sunlight. To understand the operating features of multifunctional materials, bioinspired multi-layer actuators represent a simple solution as a testing platform. Here, we report the fabrication of a bilayer photothermal and biodegradable bending actuator, based on thermal expansion of polycaprolactone-lignin blend, 3D printed on cellulose acetate substrate. When the actuator is irradiated with 300 mW/cm2 of simulated solar irradiance, it shows a change in curvature of 25.34%, with a bending moment of ~80.2 µN · m and with a characteristic actuation time of 30 s. Moreover, the photothermal blend shows a conversion efficiency of 13.5%. Due to the photothermal and biodegradability properties, the actuator could be used as a battery-free tool for different tasks, in a scenario where no contamination of the environment is required.
Translation-Like Isoptic Surfaces and Angle Sums of Translation Triangles in $$\textbf{Nil}$$ Geometry
Authors: Csima Géza , Szirmai Jenő 
Published: July 2023

AbstractAfter having investigated the geodesic and translation triangles and their angle sums in$$\textbf{Sol}$$Soland$$\widetilde{{\textbf{S}}{\textbf{L}}_2{\textbf{R}}}$$SL2R~geometries we consider the analogous problem in$$\textbf{Nil}$$Nilspace that is one of the eight 3-dimensional Thurston geometries. We analyze the interior angle sums of translation triangles in$$\textbf{Nil}$$Nilgeometry and we provide a new approach to prove that it can be larger than or equal to$$\pi $$π. Moreover, for the first time in non-constant curvature Thurston geometries we have developed a procedure for determining the equations of$$\textbf{Nil}$$Nilisoptic surfaces of translation-like segments and as a special case of this we examine the$$\textbf{Nil}$$Niltranslation-like Thales sphere, which we callThaloid. In our work we will use the projective model of$$\textbf{Nil}$$Nildescribed by Molnár (Beitr Algebra Geom 38(2):261–288, 1997).