Working towards a carbon-neutral future requires countries to decrease fossil fuel utilisation which is closely related to decreasing the natural gas dependence of countries. The utilisation of ...energy sources within the countries is preferable, for example by increasing biogas production and utilising materials used to a smaller extent. Such bioresources may be various freshwater macrophytes, especially such specimens that are quick to spread due to their invasive nature. If the atmospheric carbon dioxide bound by these macrophytes is not turned into methane via anaerobic digestion but the plants are used as base material, it could be a significant step to achieve a carbon-neutral future. In the article, various biogas production experiments with these plants are reviewed, focusing on the gas and methane yield from the mono- and co-digestion of the different plants, including the possible pre-treatment methods, and the disadvantages of their use. The biogas yield of freshwater macrophytes is generally between 200 and 400 Lgas/kgVS which can be increased with co-digestion in most cases. The use of aquatic plants after phytoremediation has not been fully explored yet, but the results so far indicate that biogas production is not hindered by the bound elements. The co-digestion experiments revealed that the addition of aquatic plants in 25–50 % to the base material produces the best gas and methane yield values. Various pre-treatment methods can be used to process aquatic plants before anaerobic digestion. Comminution and thermal treatment can increase gas yield but the effect of chemical pre-treatment depends on the type of chemical used. The utilisation of freshwater macrophytes in biogas production could be successfully up-scaled, as the pilot-sized experiments showed promising results.
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•The utilisation of freshwater macrophytes as a raw material for biogas is reviewed.•These are suitable for mono-digestion, optimally in 25–50 % w/w for co-digestion.•The biogas yield can be increased by pre-treating the aquatic plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The focus of our research is the examination of Hermitian curves over finite fields, specifically concentrating on places of degree three and their role in constructing Hermitian codes. We begin by ...studying the structure of the Riemann-Roch space associated with these degree-three places, aiming to determine essential characteristics such as the basis. The investigation then turns to Hermitian codes, where we analyze both functional and differential codes of degree-three places, focusing on their parameters and automorphisms. In addition, we explore the study of subfield subcodes and trace codes, determining their structure by giving lower bounds for their dimensions. This presents a complex problem in coding theory. Based on numerical experiments, we formulate a conjecture for the dimension of some subfield subcodes of Hermitian codes. Our comprehensive exploration seeks to deepen the understanding of Hermitian codes and their associated subfield subcodes related to degree-three places, thus contributing to the advancement of algebraic coding theory and code-based cryptography.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper is a survey of
location-routing: a relatively new branch of locational analysis that takes into account vehicle routing aspects. We propose a classification scheme and look at a number of ...problem variants. Both exact and heuristic algorithms are investigated. Finally, some suggestions for future research are presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The co-pyrolysis and co-gasification of woody biomass (oak) blended with food waste in a 2:1 ratio were investigated in a fixed bed tubular reactor. Gas compositions, gas yields, LHVs, H2/CO ratios ...and carbon conversions were evaluated between 700 and 900 °C reactor temperature and 7–22 g h−1 steam flow rate. The highest LHV of 11.03 MJ m−3 was measured during gasification at 900 °C reactor temperature with 7 g h−1 steam flow, and the LHV remained similar in both pyrolysis and gasification period. Typically, the H2/CO ratio ranged between 0.53 and 0.81 during pyrolysis, however, the ratio decreased by increasing the temperature. The gasification performed at 900 °C reactor temperature and 22 g h−1 steam flow resulted the most promising H2/CO ratio of 2.03 which has a great potential for further chemical processing. Additionally, the highest carbon conversion (99.7%) and gas yield (888.7 l kg−1) were measured at these conditions. Based on the results the co-pyrolysis and co-gasification of woody biomass and food waste is a viable method to reduce the accumulation of food waste and generate value added products.
•Co-pyrolysis and co-gasification of food waste and woody biomass is demonstrated.•The influence of reactor temperature and steam flow rate are investigated.•Gas heating values remained similar in both pyrolysis and gasification period.•Process parameters highly influenced the H2/CO ratio in the gasification period.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
It is known that correlation-immune (CI) Boolean functions used in the framework of side channel attacks need to have low Hamming weights. The supports of CI functions are (equivalently) simple ...orthogonal arrays, when their elements are written as rows of an array. The minimum Hamming weight of a CI function is then the same as the minimum number of rows in a simple orthogonal array. In this paper, we use Rao’s Bound to give a sufficient condition on the number of rows, for a binary orthogonal array (OA) to be simple. We apply this result for determining the minimum number of rows in all simple binary orthogonal arrays of strengths 2 and 3; we show that this minimum is the same in such case as for all OA, and we extend this observation to some OA of strengths 4 and 5. This allows us to reply positively, in the case of strengths 2 and 3, to a question raised by the first author and X. Chen on the monotonicity of the minimum Hamming weight of 2-CI Boolean functions, and to partially reply positively to the same question in the case of strengths 4 and 5.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The harmful effects of wear can be reduced through proper lubrication of the frictional parts. When exposed to excessive loads, the lubricant film is displaced from the surfaces, and even the ...adhesive lubricant layer may rupture. Additives known as Extreme Pressure (EP) are frequently incorporated into lubricants to minimise wear and avert seizures under high temperature and pressure. Mechanistically, these additives generate a film on the surface through chemisorption. These additives are extensively applied in various lubricants, with the largest quantities being employed in metalworking fluids and lubricating greases. Sulfurized vegetable oils and their derivates can be used as EP additives for lubricants. To conduct the investigations, sulfurized additives were synthesized using different vegetable-based oils and fatty acid esters, and alpha-olefins. In this study, the Four-ball test results were compared to gain a more accurate comprehension of how various raw-material-based additives influence wear and friction. The goal was to select raw materials that could be used with favorable results for the production of EP additives. The objective was to achieve a minimum Four-ball weld load parameter of 2000 N. The experiments revealed that the functional impacts of the synthesized samples are dependent on the type of raw materials employed. Based on the experimental data and the stated criteria, the examined raw materials were found to be suitable for the synthesis of EP additives.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•The review covers nanomaterials, fibers, polymers, microbes, and industrial waste materials.•The physicochemical properties of additives used in soil stabilization are discussed.•The interaction ...mechanisms between collapsible soils and additives are reviewed.•The mechanical properties of stabilized collapsible soils are highlighted.•The challenges and research gaps of collapsible soil stabilization are identified.
Collapsible soils are susceptible to high and relatively sudden volume change after wetting under a specific load. They tend to have a high initial void index (more than 40%), a low saturation degree (less than 60%), a high silt content (greater than 30%), and quick softening after reaching humidity (loss of bonding). Due to the settlement of the underlying soil after wetting, collapsible soils under the foundation of industrial or residential buildings can cause irreversible and significant damage to the supporting structures. In recent years, more attention has been paid to enhancing the physical and mechanical properties of collapsible soils. This research has comprehensively investigated the feasibility and efficiency of treating collapsible soils with a great variety of stabilization materials including nanomaterials, fibers, polymers, industrial waste materials, and biological techniques. Collapse potential, shear strength parameters, unconfined compressive strength (UCS), permeability reduction, swelling, and durability improvement of treated collapsible soils were investigated. This paper discusses the mechanism of how each material enhances the strength of the soil. According to previous research, using a small amount of nanomaterials, fibers, and polymers (less than 4% of dry mass soil) resulted in a significant change and improvement in soil parameters. However, for industrial waste materials, such as textile slug and marble dust, more proportions (about 30%) would be beneficial.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•VNS-triggered memory extraction improves method performance up to 5.2%.•Incorporating real life aspects could improve daily total routing cost up to 8%.•Vehicle capacity and working time utilization ...could be improved by up to 12.5%.•Real life aspects could improve fleet composition at no extra cost.•Interesting managerial insights regarding real life routing trade-offs.
In this paper we consider a real life Vehicle Routing Problem inspired by the gas delivery industry in the United Kingdom. The problem is characterized by heterogeneous vehicle fleet, demand-dependent service times, maximum allowable overtime and a special light load requirement. A mathematical formulation of the problem is developed and optimal solutions for small sized instances are found. A new learning-based Population Variable Neighbourhood Search algorithm is designed to address this real life logistic problem. To the best of our knowledge Adaptive Memory has not been hybridized with a classical iterative memoryless method. In this paper we devise and analyse empirically a new and effective hybridization search that considers both memory extraction and exploitation. In terms of practical implications, we show that on a daily basis up to 8% cost savings on average can be achieved when overtime and light load requirements are considered in the decision making process. Moreover, accommodating for allowable overtime has shown to yield 12% better average utilization of the driver's working hours and 12.5% better average utilization of the vehicle load, without a significant increase in running costs. We also further discuss some managerial insights and trade-offs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Despite extensive research into dynamic and operational capabilities, understanding of their interplay is still scant. Both complementary and substitutive roles have been proposed in prior conceptual ...studies, but only limited systematic empirical investigations into the mutual interdependence of these capabilities have been conducted. Drawing on a sample of 219 Hungarian B2B firms, this study incorporates prior literature on dynamic and operational capabilities and employs a set-theoretical approach to examine whether the capabilities complement or substitute each other in producing high levels of business performance. While evidence for both types of interdependency is provided, the findings generally support the view that dynamic and operational capabilities are complementary rather than substitutive. The two types of capabilities also explain business performance better jointly than in isolation. Several effective capability configurations, associated with high business performance, are identified. The findings paint a detailed picture of the complex interplay between dynamic and operational capabilities, thereby contributing to academic and managerial audiences alike.
•The results support to the view that customer focus and product orientation are two distinct objectives that appear difficult to reconcile. However, configuration analyses show that some firms may still be able to manage customer-centric product development if other capabilities are in place, and if such capability configurations match internal and external organizational contingencies.•The hierarchical interrelatedness of dynamic capabilities and their stimulating effect on operational capabilities and business performance appears to have empirical support but remains relatively scarce across configurations and different types of performance outcomes.•Dynamic capabilities can themselves contribute to high financial performance.•Moreover, the configurations imply that most of the operational and dynamic capabilities co-occur with a high level of competitive intensity and, in some cases (though with less frequency), with a high level of technological turbulence.•In addition, the results indicate that small firms may not be able to manage a wide range of capabilities and are more likely to developing their core activities (/competencies) and specializing in specific skills.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study aimed to develop a novel radiotracer using trastuzumab and the long-lived 52MnMn isotope for HER2-targeted therapy selection and monitoring. A new Mn(II) chelator, BPPA, synthesized from ...a rigid bispyclen platform possessing a picolinate pendant arm, formed a stable and inert Mn(II) complex with favorable relaxation properties. BPPA was converted into a bifunctional chelator (BFC), conjugated to trastuzumab, and labeled with 52MnMn isotope. In comparison to DOTA-GA-trastuzumab, the BPPA-trastuzumab conjugate exhibits a labeling efficiency with 52MnMn approximately 2 orders of magnitude higher. In female CB17 SCID mice bearing 4T1 (HER2−) and MDA-MB-HER2+ (HER2+) xenografts, 52MnMn-BPPA-trastuzumab demonstrated superior uptake in HER2+ cells on day 3, with a 3–4 fold difference observed on day 7. Overall, the hexadentate BPPA chelator proves to be exceptional in binding Mn(II). Upon coupling with trastuzumab as a BFC ligand, it becomes an excellent imaging probe for HER2-positive tumors. 52MnMn-BPPA-trastuzumab enables an extended imaging time window and earlier detection of HER2-positive tumors with superior tumor-to-background contrast.
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