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Dissolution behaviour of black alder bark extractives in polyurethane synthesis media: A comprehensive study
2024
Lauberts, Maris | Pals, Matiss | Ponomarenko, Jevgenija | Arshanitsa, Alexandr
Two approaches to incorporating black alder (BA) bark extractives-derived polyol into a polyurethane (PU) network were studied. In the first case, fractionation of bark extractives with tetrahydrofuran (THF), focusing on isolating the biomass fraction available for obtaining PU elastomers by casting methods using cyclic ethers as a solvent, was employed. Another approach aimed to obtain liquid bio-polyols that could be suitable for producing rigid PU foams. For this purpose, oven-dried crude BA bark water extracts were liquefied with polyethylene glycol (PEG 400) at temperatures of 130–170 °C. The effect of adding sulfuric acid as a catalyst on biomass processing was studied. Wet chemistry, GC, FTIR spectroscopy, analytical pyrolysis (PyGC/MS/FID) and rheological methods were employed to characterize the obtained polyols and insoluble fractions, enabling an assessment of biomass transformation during processing. The resulting THF-soluble fraction comprised 62% of the BA bark extract, mainly consisting of the xyloside form of the diarylheptanoid compound oregonin, along with oligomeric flavonoids and carbohydrates. The THF-insoluble fraction was most enriched with carbohydrate compounds. Moreover, it was observed that the PEG 400-insoluble fractions were predominantly composed of carbohydrate components. The results indicated that the use of sulfuric acid as a catalyst (1–1.5% of solvent) promotes the complete liquefaction of extractives, enabling biomass content in polyols of up to 15–25%. Surpassing the extract content in the starting suspension up to 30% resulted in incomplete liquefaction of biomass. These findings offer valuable insights into tailoring BA bark extractives as building blocks suitable for obtaining PU materials.
Afficher plus [+] Moins [-]Data acquisition system for vehicle engine sensors: A review
2024
Melders, Lauris | Smigins, Ruslans | Birkavs, Aivars
Monitoring the operation of car engines using a smartphone and cloud services is a concept that falls within the field of intelligent vehicle technologies. Using information collection system, vehicle fleet companies can effectively manage the usage of their vehicles, minimizing investment and maintenance costs, preventing accidents and failures, identifying poor driving behaviour among employees, and reducing expenses associated with fuel, tires, and other resources. This approach involves collecting real-time data from the vehicle engine sensors, transferring data to the cloud via a smartphone, and then using cloud services to analyse and manage the information, making it understandable in a simple way. This review reflects on the working efficiency of internal combustion engines and the reduction of pollution to the environment, also gathers existing literature to gain insights into vehicle sensor data acquisition technology and systems in the automotive industry identifying gaps in current knowledge and provide a conceptual framework for next practical research in this field. After explaining the general idea of logistics tasks in technology development, various sensors and their methods are associated with engine properties are introduced. The research results show that most articles are about data acquisition systems from different systems. They can provide convenience and flexibility for users, allowing them to easily access and adjust settings on-the-go, enabling real-time monitoring and adjustment of engine performance, helping users optimize efficiency and performance based on their specific needs and preferences.
Afficher plus [+] Moins [-]The deformation monitoring system on the Brasa overpass in Riga [Latvia]
2024
Kraskevičs, Edgars | Celms, Armands | Rusinovs, Jevgenijs
Engineering structures such as bridges, overpasses, and viaducts constitute a crucial component of the infrastructure of any industrial city. The wide-scale industrialisation of the twentieth century transformed the urban landscape. Many designs and solutions have become morally and physically outdated since those times, yet their usage continues, which is not always safe. With the aging of infrastructure, the issue of their further safe use inevitably arises. Geodetic monitoring of structural deformations can provide control and safety, as well as gather data for designers and engineers. The data collected by deformation monitoring systems should form the basis for the reconstruction and maintenance project of infrastructural facilities. Deformation monitoring systems are designed for each object based on the parameters of the structure, taking into account the constructive features, materials, and the importance of the infrastructural object to the city traffic. It is not always possible to completely close an overpass during reconstruction, as this would affect the transport flow in a specific district of the city. Monitoring of recently put into operation structures will ensure the collection of deformation data for the survival analysis. Once the structural health is defined, the period of service life until scheduled maintenance will be determined. As a result of our research on the Brasa overpass in Riga, we developed a scheme for swift response to signals from the monitoring systemʼs sensors. Additionally, we ensured the safe operation of the old overpass during the construction of the new one by promptly utilising data obtained from the deformation monitoring system.
Afficher plus [+] Moins [-]Robotic process automation in small and medium enterprises – a review
2024
Kļaviņš, Atis
Robotic process automation (RPA) is relatively new software technology that is quickly being adopted by companies around the globe to free office workers from routine, monotonous and rule-based tasks letting them invest their time in higher complexity and value tasks. While big companies have money, time and workforce resources to implement RPA, small and medium enterprises (SME) fall behind in their effort to start using RPA despite the fact that for this segment of organizations RPA would be useful as it presents the opportunity to re-arrange their limited resources and delegate part of work to software. To address this situation, the aim of this paper is to conduct systematic review of literature regarding RPA appliances in enterprises in order to find out how to implement RPA successfully, what processes to give to RPA, and how SMEs can implement RPA better. During the review main guidelines on how to implement RPA in enterprise in general and which processes to delegate to RPA in particular were identified as well as challenges RPA implementation might bring to company. It was also noted that there is missing research on how to adopt RPA specifically in SMEs segment. The conclusion is that SMEs aimed RPA implementation guidelines are missing.
Afficher plus [+] Moins [-]Engaging women in microfinance: A qualitative study of the Programme de Microfinance Rural in Mali
2024
Margolies, Amy | Heckert, Jessica | Meinzen-Dick, Ruth S.
The Programme de Microfinance Rural (PMR) was implemented in the rural, impoverished regions of Koulikoro, Kayes, Ségou, Sikasso and Mopti in Mali with support from the International Fund for Agricultural Development (IFAD). This paper shares the results of a qualitative study designed to improve understanding of the programme’s delivery and explore its impacts in terms of collective agency and efficacy, as well as the use of resources in households, with attention paid to the role of gender in addressing these issues. The findings suggest that the PMR actively engaged women and expanded access to loans through community-based credit groups. It also overcame negative community experiences with previous microfinance programmes to maintain a positive local reputation. In many cases, the PMR led to significant economic benefits for women but, in other cases, loan repayment terms posed a challenge. The collective agency of PMR credit groups built upon progress made by similar community groups in existence prior to the arrival of the PMR. The resources provided by the PMR strengthened these groups and helped enable them to expand their collective efficacy and ability to benefit the community more broadly. Women were most often the target loan recipients and frequently had a strong voice in the PMR groups, which were influential in the community. There is little evidence, however, that the PMR activities and credit group participation spilled over to strengthen either women’s political power in the community or their influence and empowerment in their own households. The paper concludes with specific recommendations for strengthening future iterations of the PMR or similar programmes.
Afficher plus [+] Moins [-]Circular bioeconomy for sustainable resource management and livelihood improvement in Ethiopia
2024
Bodach, Susanne | Alegbeleye, Oluwadara | Taron, Avinandan | Hagos, Fitsum
Ethiopia faces a growing challenge of balancing natural resource utilisation with long-term sustainability. Its linear economic model leads to unsustainable waste generation from agriculture, urban populations, and the industry sectors. This paper explores the potential of a circular bioeconomy (CBE) as a solution. By promoting closed-loop systems that minimise waste and maximise resource use, CBE offers a pathway for Ethiopia to achieve sustainable resource management, economic growth, and better livelihood opportunities. CBE business models create valuable products such as organic fertiliser, biochar, bioenergy, and alternative proteins. CBE practices provide new income opportunities for farmers and urban dwellers and reduce the country’s reliance on virgin resources, chemical fertiliser, and non-renewable energy while addressing environmental pollution and soil depletion. Major organic waste streams in Ethiopia that could be recovered and reused include agricultural crop residues, animal manure, human excrement, and industrial sludge. Addressing the vast untapped potential of resource recovery from waste, this study analyses opportunities and challenges associated with promoting CBE in Ethiopia, focusing on analysing the regulatory framework, business licensing and registration procedure, government support, access to finance, and business support services. The paper employs a comprehensive desk review of peer-reviewed literature complemented by grey literature to capture recent trends or non-traditional research aspects. Semi-structured interviews with sector experts were conducted to fill information gaps. Key findings of this study are that a robust regulatory framework, streamlined business registration, and access to finance are critical for creating an enabling investment climate for CBE. Government support, business networks, and support services can empower CBE ventures and contribute to sustainable resource management. By focusing on policy interventions that combine sustainable waste management and livelihood creation, CBE can significantly contribute to achieving a more sustainable development path for all Ethiopians.
Afficher plus [+] Moins [-]Tank cascade system: A nature-based solution for achieving climate resilience in Sri Lanka’s dry zone
2024
Ratnayake, Sujith S. | Mendonce, Sharon | Borelli, Teresa | Hunter, Danny | Silva, Ajith | Dissanayake, Thushani
The Tank Cascade System (TCS) is an ancient, man-made rainwater harvesting and irrigation system unique to Sri Lanka’s dry zone. An ecosystem in itself, the TCS consists of an intricate network of small to large ‘tanks’ positioned along a gradient and connected through a series of canals. Within the system, paddy fields and dense forests coexist providing habitats for socio-ecologically significant species. Historically, the system has been crucial in drought and flood mitigation. Furthermore, fully functioning TCSs harvest copious amounts of rainwater, which is primarily used for irrigation to enable year-round crop production by the farming communities of the cascade landscape. The system’s important role in food security, rural livelihoods and local culture led to its designation as a Globally Important Agricultural Heritage System in 2017. Despite the TCS’s significance, the system has been deteriorating, and its sustainability is threatened by widespread tank neglect, rapid land use changes and biodiversity loss –the impacts of which are exacerbated by the effects of climate variability. There is national interest in safeguarding the TCS, though. The system has been recognized in Sri Lanka’s 2016-2025 National Adaptation Plan for Climate Change Impacts and within the 2021 Nationally Determined Contributions as an important Nature-based Solution (NbS) for strengthening national climate resilience. However, there is little evidence of this national support translating into on the ground action and of effective solutions to the challenges threatening TCS sustainability. This case study aims to fill these evidence gaps by sharing findings from research and project activities carried out under the Healthy Landscapes project. With a special focus on mainstreaming biodiversity and strengthening cascade ecology, the project rehabilitated and promoted the sustainable management of the TCS. This case study will highlight pathways for TCS rehabilitation to strengthen its function as a NbS, including associated challenges and further opportunities. As the cascade landscape community plays an important role in climate adaptation and resilience within the country's dry zone, we also emphasize the importance of investigating their perceptions of current national policy and formulating localized adaptation strategies that benefit climate resilience, food security and rural livelihoods.
Afficher plus [+] Moins [-]Future research directions for understanding the interconnections between climate change, water scarcity, and mobility in rural Central Asia
2024
Hermans, K. | Djanibekov, N. | Abdullaev, Iskandar | Abduvalieva, N. | Assubayeva, A. | Blondin, S. | Bobojonov, I. | Conrad, C. | Herzfeld, T. | Kansiime, J. | Kimsanova, B. | Laldjebaev, M. | Mirkasimov, B. | Mirzabaev, A. | Murzakulova, A. | Rajabova, S. | Samakov, A. | Schraven, B. | Sterly, H. | Umirbekov, A.
Central Asia faces substantial water scarcity due to increasing water demand driven by rapid urbanization, population growth, economic development, and inefficiency of irrigated agriculture. These developments are compounded by the effects of climate change, such as rising temperatures, loss of glacier mass and increased frequency of extreme events, including droughts. The region’s escalating water scarcity is causing disputes and straining rural livelihoods. Moreover, these challenges drive migration, creating considerable societal impacts. However, these issues remain underexplored in climate change research, making the region a global blind spot in climate adaptation and migration studies. We advocate for innovative research pathways that scrutinize smallholder adaptation strategies, examine the nexus between climate change, water scarcity, and mobility, and investigate tensions and cooperation over water resources. We conclude by emphasizing that substantial investments in inter- and transdisciplinary collaboration, improved data availability and quality, and strengthening of research and institutional capacities are essential to advance interdisciplinary climate impact research in Central Asia. Such efforts are vital for addressing existing knowledge gaps and enhancing evidence-based policymaking to improve the region’s position in current and future debates on climate change and sustainable development.
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