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Challenges, Volume 11, Issue 2 (December 2020) – 20 articles

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Article
Exploratory Sampling of Spalting Fungi in the Southern Peruvian Amazon Forest
Challenges 2020, 11(2), 32; https://doi.org/10.3390/challe11020032 - 20 Dec 2020
Viewed by 769
Abstract
Most of the research related to Peruvian Amazon fungi is focused on edible mushrooms and pathogens. Other important fungi, such as the spalting type (decay fungi that pigment wood internally), are not broadly studied, as most of them do not produce fruiting bodies [...] Read more.
Most of the research related to Peruvian Amazon fungi is focused on edible mushrooms and pathogens. Other important fungi, such as the spalting type (decay fungi that pigment wood internally), are not broadly studied, as most of them do not produce fruiting bodies and can be difficult to locate. Spalting fungi, however, are of broad economic importance due to their ability to produce pigments that enhance wood aesthetics, resulting in an increased economic value. In order to begin understanding the diversity of spalting fungi within certain regions of the Amazon, a sampling of downed trees and branches (through the opening of the xylem to identify potential pigmenting and zone line producing fungi) was done in the district of Las Piedras, Madre de Dios, Peru. Fungi suspected of causing internal pigment and zone lines were collected, cultured, isolated, and sequenced. The species found belonged to the orders Helotiales, Xylariales, Hypocreales, Russulales, Polyporales, Botryosphaeriales and two specimens of the class Leotiomycetes. The fungi collected produced pigments or zone lines in wild conditions and all of them were capable of wood decomposition. Interestingly, these are the same orders and genera as North American spalting fungi, which may indicate a correlation within species that pigment wood. The results obtained start a specific database of spalted fungi in the Amazon and, with it, help support an effort to increase the forest value of ecosystems primarily used for a few high-valued tree species. Full article
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Review
An Overview of Mobile Learning for Refugee Students: Juxtaposing Refugee Needs with Mobile Applications’ Characteristics
Challenges 2020, 11(2), 31; https://doi.org/10.3390/challe11020031 - 16 Dec 2020
Cited by 1 | Viewed by 1181
Abstract
The mass influx of refugees into Europe since 2013 and their educational challenges have increased the need for high-quality refugee education. One proposal for addressing these challenges was to leverage mobile devices for educational purposes (mobile learning). Although significant research has been done [...] Read more.
The mass influx of refugees into Europe since 2013 and their educational challenges have increased the need for high-quality refugee education. One proposal for addressing these challenges was to leverage mobile devices for educational purposes (mobile learning). Although significant research has been done in this field, mobile learning’s effectiveness on different social groups has yet to be explored. The present review paper aims to outline: (a) the factors that challenge refugee education, (b) the use of smart mobile devices by the refugee population, (c) the conflicting views about the effect of mobile learning in refugee education, and (d) the proposed characteristics for mobile refugee applications as found in the literature. A juxtaposition of refugee needs with the characteristics of mobile learning apps is attempted. By surveying the literature, the present paper concludes that mobile learning seems beneficial for refugees in two ways: providing refugees access to education and improving the quality of the provided refugee education. However, it is not a one-solution-fits-all regarding their education. At the end, future research proposals are included. Full article
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Article
Methods of Promoting Professional Agency at Work
Challenges 2020, 11(2), 30; https://doi.org/10.3390/challe11020030 - 04 Dec 2020
Viewed by 838
Abstract
In the midst of continuous changes in working life, finding a way to balance organizational demands and the needs of employees has become an important task. This task has highlighted the significance of agency and social interaction, as influencing factors that can enhance [...] Read more.
In the midst of continuous changes in working life, finding a way to balance organizational demands and the needs of employees has become an important task. This task has highlighted the significance of agency and social interaction, as influencing factors that can enhance people’s potential to meet new learning tasks. In the Scandinavian and Finnish contexts, research institutions, in cooperation with work organizations, have developed practical methods to promote agency and learning at work. The objective of this study is to evaluate the potential of two different workplace development methods, identity (ID) training, and participatory action research (PAR) using dialogue forums if combined and applied as a two-level approach. The study asks what the characteristics of these methods are in general and if there are any key characteristics that could support their combined application. The research question is answered by a qualitative descriptive analysis of the literature on organizations, agency, and applications of the methods. The results shed light on and emphasize the intertwining characteristics of the methods. The research concludes with the hypothesis—to be tested in further research—that the methods are necessary for each other and recommends a preliminary investigation on the prevailing organizational culture, as a resource for organization-specific modifications. Full article
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Perspective
Indigenous Natural and First Law in Planetary Health
Challenges 2020, 11(2), 29; https://doi.org/10.3390/challe11020029 - 28 Oct 2020
Cited by 5 | Viewed by 3035
Abstract
Indigenous Peoples associate their own laws with the laws of the natural world, which are formally known as or translated as Natural or First Law. These laws come from the Creator and the Land through our ancestral stories and therefore, they are sacred. [...] Read more.
Indigenous Peoples associate their own laws with the laws of the natural world, which are formally known as or translated as Natural or First Law. These laws come from the Creator and the Land through our ancestral stories and therefore, they are sacred. All aspects of life and existence depend on living and following these natural First Laws. Since colonization, Indigenous Peoples’ Natural Laws have been forcibly replaced by modern-day laws that do not take into account the sacred relationship between the Earth and all of her inhabitants. The force of societies who live outside of Natural Law has ensured the modern-day consequences of not living in balance with nature. Pandemics and global environmental change, including climate change, are all consequences of not following the Natural Laws that are encapsulated by the interconnected nature of the universe. Here we discuss Natural Law from an Indigenous paradigm and worldview which carries implications for planetary health and wider environmental movements around the globe. Full article
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Article
A Systems Approach to Building Community Capacity and Resilience
Challenges 2020, 11(2), 28; https://doi.org/10.3390/challe11020028 - 20 Oct 2020
Cited by 1 | Viewed by 1243
Abstract
Capacity and resilience are two closely aligned concepts in human development. They both contribute to increasing the ability of societies to cope with and adapt to challenging and adverse perturbations that may affect systems the societies depend upon. A traditional approach to building [...] Read more.
Capacity and resilience are two closely aligned concepts in human development. They both contribute to increasing the ability of societies to cope with and adapt to challenging and adverse perturbations that may affect systems the societies depend upon. A traditional approach to building capacity and resilience at the community scale is to address in a fragmented manner specific issues at play in institutional, socio-economic, environmental, and infrastructure systems that may prevent the delivery of adequate community services and meeting development goals. This compartmentalized approach, driven by a need to reach some form of satisfactory community equilibrium, fails to recognize the interactions and interconnectedness that exist among community systems, which, if addressed, could solve multiple issues more effectively. It also does not account for the complex, adaptive, and dynamic nature of communities. A resilient community is more than just a collection of well-functioning silos. This paper proposes a system dynamics approach to account for the dynamic and adaptive nature of communities when developing capacity-building strategies toward strengthening their ability to deliver services and deal with adverse events. A case study of small-scale community capacity assessment around the service of wastewater and sewage treatment published elsewhere is presented to illustrate the proposed approach. Full article
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Communication
Resilience Thinking and Strategies to Reclaim Sustainable Rural Livelihoods: Cascade Tank-Village System (CTVS) in Sri Lanka
Challenges 2020, 11(2), 27; https://doi.org/10.3390/challe11020027 - 16 Oct 2020
Viewed by 1127
Abstract
Cascading Tank Village Systems (CTVSs) of Sri Lanka historically provided a resilient community-based social-ecological water management system in the rural dry zone of Sri Lanka After being abandoned for many centuries, their restoration is now being pursued by different national and international actors [...] Read more.
Cascading Tank Village Systems (CTVSs) of Sri Lanka historically provided a resilient community-based social-ecological water management system in the rural dry zone of Sri Lanka After being abandoned for many centuries, their restoration is now being pursued by different national and international actors as a key to climate change mitigation and sustainable livelihoods for communities. Rural livelihoods in the dry zone are at risk due to multiple factors, poor access and management of water, economic and health pressures, as well as resource limitations and degradation. Despite recent efforts to restore CTVS systems, no social-ecological approach (SES) nor a sustainable livelihoods framework (SLF)-focused approach to ensuring resilient and sustainable livelihood outcomes has been taken. As part of an on-going PhD project, this paper analyses the background, current challenges and potential for an SES focused resilience thinking approach to CTVS for future sustainable livelihood opportunities and outcomes. The study finds CTVS exhibit all the properties of a complex adaptive SES and that a resilience thinking approach centred on achieving sustainable livelihood outcomes for communities suggests deep institutional changes are needed. CTVS are at a crossroads between restoring the past (system adaptability) or transforming for the future, and a combination of legacy and future market orientation seems the best solution. Full article
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Viewpoint
Current Challenges of Cold Brew Coffee—Roasting, Extraction, Flavor Profile, Contamination, and Food Safety
Challenges 2020, 11(2), 26; https://doi.org/10.3390/challe11020026 - 13 Oct 2020
Cited by 2 | Viewed by 1602
Abstract
Cold brew coffee has emerged as a new trend over the last decade. However, “cold brew” is an extraction style of ground roasted coffee with water at lower than body temperature (typically 8 °C or room temperature), rather than a beverage per se. [...] Read more.
Cold brew coffee has emerged as a new trend over the last decade. However, “cold brew” is an extraction style of ground roasted coffee with water at lower than body temperature (typically 8 °C or room temperature), rather than a beverage per se. Cold brew extraction poses several challenges, including the need for specific optimization depending on the multiple influences of coffee variety and processing, roast degree, grinding, dosage, water composition, turbulence, brew system (drip, immersion etc.), time and temperature, and their interactions. While cold brew is typically characterized by a floral sweetness, over-extraction may lead to abundant acidity and bitterness. To avoid this, an extraction degree of 70% was suggested using shorter time frames (i.e., 2 h at 15 °C with 80 g/L coffee for optimized medium roast profiles). Due to the lack of sterilizing temperatures during preparation, cold brew is significant in the coffee sector because hygiene and food safety requirements pose specific challenges. To avoid microbiological contamination and deterioration in quality, cold brew should be as freshly prepared as possible and shelf-life should be minimized. Full article
(This article belongs to the Section Trends)
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Review
The Potential Effects of Short-Chain Fatty Acids on the Epigenetic Regulation of Innate Immune Memory
Challenges 2020, 11(2), 25; https://doi.org/10.3390/challe11020025 - 12 Oct 2020
Cited by 1 | Viewed by 1062
Abstract
The regulation of innate immunity is substantially more ‘plastic’ than previously appreciated. Innate immune memory (manifested through trained immunity and tolerance) is a recently described epigenetic phenomenon that is a model example, with broad implications for infectious disease, allergy and autoimmunity. Training the [...] Read more.
The regulation of innate immunity is substantially more ‘plastic’ than previously appreciated. Innate immune memory (manifested through trained immunity and tolerance) is a recently described epigenetic phenomenon that is a model example, with broad implications for infectious disease, allergy and autoimmunity. Training the innate immune system to combat infections and temper inappropriate responses in non-communicable diseases will likely be an area of intense research. Innate immunity is influenced by short chain fatty acids, which are the natural products of digestion by the intestinal microbiota that possess inherent histone deacetylase inhibitory properties. It therefore stands to reason that a healthy gut microbiome may well influence mucosal and systemic trained immunity via short chain fatty acids. There is a lack of data on this specific topic, and we discuss potential relationships based on available and preliminary evidence. Understanding the link between intestinal microbiome composition, capacity for short chain fatty acid production and downstream effects on innate immune memory in early life will have important implications for host immunobiology. In this review we explore the intersection between the gut microbiota, short chain fatty acids and epigenetic regulation of innate immunity with a focus on early life. Full article
(This article belongs to the Section Trends)
Concept Paper
Concept of a Sino-German Summer School on Multiscale Processes in Oceans and the Atmosphere
Challenges 2020, 11(2), 24; https://doi.org/10.3390/challe11020024 - 24 Sep 2020
Viewed by 1124
Abstract
A concept for an interdisciplinary summer school for “multiscale processes in oceans and the atmosphere” is presented. It aims to deepen students’ understanding of scientific issues as well as their experience in multicultural communication. The theme covers climate evolution, which is partially dominated [...] Read more.
A concept for an interdisciplinary summer school for “multiscale processes in oceans and the atmosphere” is presented. It aims to deepen students’ understanding of scientific issues as well as their experience in multicultural communication. The theme covers climate evolution, which is partially dominated by far-reaching anthropogenic changes and their possible consequences on the Earth’s system. An integrated approach helps to change rigid subject-specific mindsets among faculties and students and across cultures, so as to broaden their horizons in both research and life. Research has shown, however, that the development of intercultural competence in students does not happen automatically but needs to be fostered and supported. Therefore, a primary goal is also to provide young researchers from several countries (mainly China and Germany) with the opportunity to gain more indepth knowledge on research in Germany, to be exposed to scientific culture, and thus to prepare for foreign research visits either during the PhD phase or as postdoctoral fellows, supporting the internationalization of education and opportunities in marine sciences. Finally, the students have the chance to further develop their scientific profiles by attending scientific talks, lab exercises, and excursions and by combining rigorous scientific disciplines with the awareness of multidisciplinary issues related to the topic of global climate change. Full article
(This article belongs to the Special Issue Challenges: 10th Anniversary)
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Concept Paper
Systemic Crop Signaling for Automatic Recognition of Transplanted Lettuce and Tomato under Different Levels of Sunlight for Early Season Weed Control
Challenges 2020, 11(2), 23; https://doi.org/10.3390/challe11020023 - 23 Sep 2020
Cited by 3 | Viewed by 1148
Abstract
Conventional cultivation works to control weeds between the rows, but it ignores the weeds in crop rows which are most competitive with crops. Many vegetable crops still require manual removal of intra-row weeds not otherwise controlled by herbicides or conventional cultivation. The increasing [...] Read more.
Conventional cultivation works to control weeds between the rows, but it ignores the weeds in crop rows which are most competitive with crops. Many vegetable crops still require manual removal of intra-row weeds not otherwise controlled by herbicides or conventional cultivation. The increasing labor costs of weed control and the continued emergences of herbicide-resistant weeds are threatening grower ability to manage weeds and maintain profitability. Intra-row weeders are commercially available but work best in low weed populations. One strategy for rapid weed crop differentiation is to utilize a machine-detectable compound to mark a crop. This paper proposes a new systemic plant signaling technology that can create machine-readable crops to facilitate the automated removal of intra-row weeds in early growth stages. Rhodamine B (Rh–B) is an efficient systemic compound to label crop plants due to its membrane permeability and unique fluorescent properties. The project involves applying solutions of Rh–B at 60 ppm to the roots of lettuce and tomato plants prior to transplantation to evaluate Rh–B persistence in plants under different levels of sunlight. Lettuce and tomato seedlings with the systemic Rh–B should be reliably recognized during their early growth stages. An intelligent robot is expected to be developed to identify the locations of plants based on the systemic signal inside. Reduced light treatments should help to alleviate the photodegradation of Rh–B in plants. After being exposed to full sunlight for 27 days, the systemic Rh–B would be detectable in tomato branches and lettuce ribs, and these plants are tolerant to root treatments with this fluorescent compound. This paper describes the project background and plan as well as the anticipated contributions of the research to allow the machine vision system to reliably identify the crop plants, and thus showing technical feasibility for outdoor weed control. Full article
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Perspective
A Perspective on Nigeria’s Preparedness, Response and Challenges to Mitigating the Spread of COVID-19
Challenges 2020, 11(2), 22; https://doi.org/10.3390/challe11020022 - 21 Sep 2020
Cited by 2 | Viewed by 1392
Abstract
Coronavirus disease 2019 (COVID-19) is a novel disease pandemic that emerged in late 2019 in China, and later spread to other parts of the world, including Nigeria. This review analyzes the preparedness of Nigeria to the COVID-19 pandemic and recommends strategies that could [...] Read more.
Coronavirus disease 2019 (COVID-19) is a novel disease pandemic that emerged in late 2019 in China, and later spread to other parts of the world, including Nigeria. This review analyzes the preparedness of Nigeria to the COVID-19 pandemic and recommends strategies that could be useful in controlling the disease. Published articles on COVID-19 worldwide, socioeconomic and disease status and preparedness to COVID-19 in Africa and Nigeria, were retrieved from databases such as Pubmed, MEDLINE, Scopus, Web of Knowledge and Google search engine. Nigeria is the most populous black nation in the world, and is one of the largest crude oil producers in the world. However, its healthcare system is dilapidated and weak, due to years of neglect and widespread corruption. As a result, Nigeria is vulnerable to COVID-19, as evidenced by the current geographical distribution of the disease in its population. Many socioeconomic factors could potentially facilitate the spread of COVID-19 in Nigeria. This could lead to a high caseload in the country, which could overwhelm the health care system. The application of social distancing, personal hygiene, especially hand hygiene and mask-wearing, as practiced in many countries, has proven to be effective to reduce the spread of COVID-19. In Nigeria, social distancing, in many instances, may be impracticable, given its large population, and a high density of people living in crowded conditions like slums and camps. Moreover, there is a sizeable population of internally displaced people, due to the attack by Boko Haram fighters in Northern Nigeria, and herdsmen in Southern Nigeria. The implementation of these measures is likely to be a great challenge. Nigeria has announced a complete lockdown for the containment of COVD-19, but its implementation and efficacy are doubtful, due to the same reasons previously mentioned. Full article
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Perspective
Towards Healthy Planet Diets—A Transdisciplinary Approach to Food Sustainability Challenges
Challenges 2020, 11(2), 21; https://doi.org/10.3390/challe11020021 - 18 Sep 2020
Viewed by 1552
Abstract
The future of food is one of the major world-wide challenges. In this perspective paper, we set-up a framework for a multi-disciplinary future food systems approach, building on the UN Sustainable Development Goals. We hereby combine a truly sustainable approach including social science [...] Read more.
The future of food is one of the major world-wide challenges. In this perspective paper, we set-up a framework for a multi-disciplinary future food systems approach, building on the UN Sustainable Development Goals. We hereby combine a truly sustainable approach including social science aspects combined with the One Health approach. Scientists from a large number of backgrounds have addressed four key areas that are discussed in more detail in this paper: (i) nature inspired food production, (ii) sustainable immune resilience, (iii) social and cultural change of food behavior, and (iv) food fairness. We believe that transformations to integrated future food system approaches should move beyond single solutions and can only be solved by working in transdisciplinary settings of science, society, and industry. Full article
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Article
Report on Digital Literacy in Academic Meetings during the 2020 COVID-19 Lockdown
Challenges 2020, 11(2), 20; https://doi.org/10.3390/challe11020020 - 07 Sep 2020
Cited by 2 | Viewed by 2718
Abstract
COVID-19, a novel coronavirus, was deemed a pandemic during mid-March 2020. In response, lockdowns were imposed for an indefinite period world-wide. Academic institutions were no exception. Continuing meetings of academic groups consequently necessitated online communication. Various platforms were available from which to choose [...] Read more.
COVID-19, a novel coronavirus, was deemed a pandemic during mid-March 2020. In response, lockdowns were imposed for an indefinite period world-wide. Academic institutions were no exception. Continuing meetings of academic groups consequently necessitated online communication. Various platforms were available from which to choose to encourage digital literacy. Despite alternatives, the almost overnight closure of all non-essential services at one post-secondary institution resulted in the selection of Zoom as the preferred platform for meetings until social distancing ended. In contrast, the facilitator of a unique, health-related, narrative research group at the institution—a group tailored to critical thought, communication, cooperation and creativity—considered a hybrid format private Facebook group likely to provide a more appropriate and satisfying group experience than possible with synchronous Zoom meetings. Pros and cons of both online platforms are presented along with the conditions under which each one is preferable. Positive results were evident in promoting digital literacy for this particular academic group using the hybrid format of a private Facebook group. As such, private Facebook groups hold promise in supporting digital literacy for collaborative online health-related group meetings. Unique in examining and evaluating private Facebook groups, this report holds significance for digital literacy regarding academic meetings. Full article
(This article belongs to the Special Issue Challenges: 10th Anniversary)
Viewpoint
Project Earthrise: Inspiring Creativity, Kindness and Imagination in Planetary Health
Challenges 2020, 11(2), 19; https://doi.org/10.3390/challe11020019 - 04 Sep 2020
Cited by 1 | Viewed by 1861
Abstract
The concept of planetary health blurs the artificial lines between health at scales of person, place and planet. At the same time, it emphasizes the integration of biological, psychological, social and cultural aspects of health in the modern environment. Our grandest challenges in [...] Read more.
The concept of planetary health blurs the artificial lines between health at scales of person, place and planet. At the same time, it emphasizes the integration of biological, psychological, social and cultural aspects of health in the modern environment. Our grandest challenges in the Anthropocene ultimately stem from human attitudes to each other and to our environment. However, solutions rarely confront the underlying value systems that created these interconnected problems, or the attitudes that perpetuate them. Too often, the dominant focus is on the “worst of human nature”, and devalues or neglects the importance of empathy, kindness, hope, love, creativity and mutual respect—the deeper values that unite, empower and refocus priorities of individuals and groups. Here, we call to normalize more creative, mutualistic approaches—including the perspectives of traditional and indigenous cultures—to positively influence normative value systems. We revisit the power of inspiration with the profound example of the Apollo 8 Earthrise photo which galvanized a fledgling planetary health movement over 50 years ago. Through the inaugural Earth Day that followed, we are reminded that its early organizers were not constrained in how they defined the “environment”. They and their primary speakers were as concerned about value systems as they were about pollution—that we cannot hope to solve our problems without addressing the attitudes that created them in the first place. We explore the ways in which the awe of Earthrise—and the contemporary science of creativity and studies of utopian thinking—might reinvigorate imagination, kindness and mutualism. We revisit the fundamental challenge offered by Pulitzer-Prize-winning microbiologist Rene Dubos and others in the afterglow of the Earthrise photo, and the inaugural Earth Day. This is a question of imagination: What kind of world we want to live in? Full article
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Perspective
Considerations for Comparing Video Game AI Agents with Humans
Challenges 2020, 11(2), 18; https://doi.org/10.3390/challe11020018 - 20 Aug 2020
Viewed by 1377
Abstract
Video games are sometimes used as environments to evaluate AI agents’ ability to develop and execute complex action sequences to maximize a defined reward. However, humans cannot match the fine precision of the timed actions of AI agents; in games such as StarCraft, [...] Read more.
Video games are sometimes used as environments to evaluate AI agents’ ability to develop and execute complex action sequences to maximize a defined reward. However, humans cannot match the fine precision of the timed actions of AI agents; in games such as StarCraft, build orders take the place of chess opening gambits. However, unlike strategy games, such as chess and Go, video games also rely heavily on sensorimotor precision. If the “finding” was merely that AI agents have superhuman reaction times and precision, none would be surprised. The goal is rather to look at adaptive reasoning and strategies produced by AI agents that may replicate human approaches or even result in strategies not previously produced by humans. Here, I will provide: (1) an overview of observations where AI agents are perhaps not being fairly evaluated relative to humans, (2) a potential approach for making this comparison more appropriate, and (3) highlight some important recent advances in video game play provided by AI agents. Full article
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Article
Operating Small Hydropower Plants in Greece under Intermittent Flow Uncertainty: The Case of Tsiknias River (Lesvos)
Challenges 2020, 11(2), 17; https://doi.org/10.3390/challe11020017 - 03 Aug 2020
Cited by 4 | Viewed by 1262
Abstract
In arid and semi-arid parts of the world, river exploitation is intensive, involving water storage for irrigation or hydropower generation. In Greece, 100 small hydropower plants (SHPs) take advantage of less than 10% of the hydropower potential of low flow streams (<2 m [...] Read more.
In arid and semi-arid parts of the world, river exploitation is intensive, involving water storage for irrigation or hydropower generation. In Greece, 100 small hydropower plants (SHPs) take advantage of less than 10% of the hydropower potential of low flow streams (<2 m3/s), a very small amount in relation to the 70% of the European Union. The energy policy of complete decarbonization of the country by 2023 on a national scale opens the road for new investments in SHP projects, especially in intermittent-flow streams of the Greek islands. Simulated flows by the Modello Idrologico SemiDistribuito in continuo (MISDc model) are used to construct the annual flow duration curve (FDC) to study and assess the hydropower potential of an intermittent stream (Tsiknias river, Lesvos, Greece). For Tsiknias River, but also for six other intermittent-flow rivers of Crete island, the capacity factor (CF), which represents the mean annual power of the hydropower plant, should remain >75% to exploit the river’s potential. The FDC and CF are essential in designing SHP projects in intermittent-flow streams with long no-flow periods. The development of public participatory approaches and a closer cooperation among policy makers and stakeholders should work to promote hydropower exploitation and accelerate licensing procedures. Full article
(This article belongs to the Section Renewable Energies)
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Concept Paper
Dozy-Chaos Mechanics for a Broad Audience
Challenges 2020, 11(2), 16; https://doi.org/10.3390/challe11020016 - 31 Jul 2020
Cited by 2 | Viewed by 1116
Abstract
A new and universal theoretical approach to the dynamics of the transient state in elementary physico-chemical processes, called dozy-chaos mechanics (Egorov, V.V. Heliyon Physics2019, 5, e02579), is introduced to a wide general readership. Full article
(This article belongs to the Special Issue Challenges: 10th Anniversary)
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Review
Nanotechnology as an Alternative to Reduce the Spread of COVID-19
Challenges 2020, 11(2), 15; https://doi.org/10.3390/challe11020015 - 27 Jul 2020
Cited by 13 | Viewed by 3619
Abstract
The current emerging COVID-19 pandemic has caused a global impact on every major aspect of our societies. It is known that SARS-Cov-2 can endure harsh environmental conditions for up to 72 h, which may contribute to its rapid spread. Therefore, effective containment strategies, [...] Read more.
The current emerging COVID-19 pandemic has caused a global impact on every major aspect of our societies. It is known that SARS-Cov-2 can endure harsh environmental conditions for up to 72 h, which may contribute to its rapid spread. Therefore, effective containment strategies, such as sanitizing, are critical. Nanotechnology can represent an alternative to reduce the COVID-19 spread, particularly in critical areas, such as healthcare facilities and public places. Nanotechnology-based products are effective at inhibiting different pathogens, including viruses, regardless of their drug-resistant profile, biological structure, or physiology. Although there are several approved nanotechnology-based antiviral products, this work aims to highlight the use of nanomaterials as sanitizers for the prevention of the spread of mainly SARS-Cov-2. It has been widely demonstrated that nanomaterials are an alternative for sanitizing surfaces to inactivate the virus. Also, antimicrobial nanomaterials can reduce the risk of secondary microbial infections on COVID-19 patients, as they inhibit the bacteria and fungi that can contaminate healthcare-related facilities. Finally, cost-effective, easy-to-synthesize antiviral nanomaterials could reduce the burden of the COVID-19 on challenging environments and in developing countries. Full article
(This article belongs to the Section Trends)
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Article
Surface Alteration of Borosilicate and Phosphate Nuclear Waste Glasses by Hydration and Irradiation
Challenges 2020, 11(2), 14; https://doi.org/10.3390/challe11020014 - 23 Jul 2020
Viewed by 1043
Abstract
We examined the degradation of nuclear waste borosilicate and phosphate glasses containing strong alpha-emitter 238Pu at a specific activity of 6.33 × 105 MBq/g in comparison with similar non-radioactive, non-radioactive irradiated and radioactive samples containing beta- and gamma-emitters, namely radionuclides 134 [...] Read more.
We examined the degradation of nuclear waste borosilicate and phosphate glasses containing strong alpha-emitter 238Pu at a specific activity of 6.33 × 105 MBq/g in comparison with similar non-radioactive, non-radioactive irradiated and radioactive samples containing beta- and gamma-emitters, namely radionuclides 134Cs and 137Cs. For irradiation and leaching experiments, we used borosilicate and phosphate glasses, which are well-known and currently used to immobilize high-level radioactive waste. The main focus was the observation of the surface of altered glasses. Comparative analysis of hydrolytic surface alteration of borosilicate and phosphate nuclear waste glasses reveals that the behavior of radioactive samples differs significantly from that of non-radioactive glasses. Full article
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Article
Agent-Based and System Dynamics Modeling of Water Field Services
Challenges 2020, 11(2), 13; https://doi.org/10.3390/challe11020013 - 20 Jul 2020
Cited by 1 | Viewed by 916
Abstract
This paper explores the applicability of the agent-based (AB) and system dynamics (SD) methods to model a case study of the management of water field services. Water borehole sites are distributed over an area and serve the water needs of a population. The [...] Read more.
This paper explores the applicability of the agent-based (AB) and system dynamics (SD) methods to model a case study of the management of water field services. Water borehole sites are distributed over an area and serve the water needs of a population. The equipment at all borehole sites is managed by a single water utility that has adopted specific repair, replacement, and maintenance rules and policies. The water utility employs several service crews initially stationed at a single central location. The crews respond to specific operation and maintenance requests. Two software modeling tools (AnyLogic and STELLA) are used to explore the benefits and limitations of the AB and SD methods to simulate the dynamic being considered. The strength of the AB method resides in its ability to capture in a disaggregated way the mobility of the individual service crews and the performance of the equipment (working, repaired, replaced, or maintained) at each borehole site. The SD method cannot capture the service crew dynamics explicitly and can only model the average state of the equipment at the borehole sites. Their differences aside, both methods offer policymakers the opportunity to make strategic, tactical, and logistical decisions supported by integrated computational models. Full article
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