Search

Today's increasing demand for aquaculture production is accompanied by various challenges such as diseases, broodstock improvement, domestication, development of suitable pellets and feeding methods, hatchery technology, and water quality management. Thus, probiotic usage has been reported as the ideal alternative to antibiotics, other chemotherapeutics, and additional supplements to other alternative ingredients. The main beneficial roles of probiotics include the enhancement of disease and stress resistance, immunity, promotion of growth and reproduction, improvement of digestion, provide several nutrients, and enhancement of water microbial composition. To guarantee safety, the probiotics provided must be noninvasive and non-pathogenic. The use of probiotics in aquaculture, either directly or in combination with alternative materials such as plant protein diets, vitamins, microalgae, fermented products, and so on, has been shown to improve the health and growth of aquatic animals and offer significant benefits to the sustainability of the industry. There is advocacy for a systematic approach to conducting innovative research to unearth new putative strains, which is substantial in ensuring sustainable probiotic usage and, thus, can help in the continuous development of the aquaculture industry especially in China. Some examples of the probiotics found in China are mainly photosynthetic bacteria (PSB) which are autotroph bacteria capable of photosynthesis, antagonistic bacteria (Pseudoalteromonas sp., Flavobacterium sp., Alteromonas sp., Phaeobacter sp., Bacillus sp., etc.), bacteria that contribute nutrients and enzymes during digestion (lactic acid bacteria, yeasts, etc.), bacteria that improve water quality (nitrifying bacteria, denitrifying bacteria, etc.), Bdellovibrio, and other probiotics. This review also focuses on the potential use of probiotics in aquaculture, especially in China, and probiotics' prospective future role. [ABSTRACT FROM AUTHOR]

A new sintering technique as a combination of ultra-fast spark plasma sintering and high-pressure sintering was employed to densify UO 2 fuel pellets. UO 2 pellets with a relative density of 97.5 % and inhibited grain growth were fabricated at 1000 °C under 150 MPa within only 4.5 min. Both short sintering time and high pressure might explain the inhibited grain growth and hence finer microstructures. UO 2 fuel pellets prepared in this work exhibit excellent mechanical properties. [ABSTRACT FROM AUTHOR]

Large-grained UO2 is considered a potential accident-tolerant fuel (ATF) due to its superior fission gas retention capabilities. Irradiation experiments for cerium dioxide (CeO2), used as a surrogate fuel, is a common approach for evaluating the performance of UO2. In this work, spark plasma sintered CeO2 pellets with varying grain sizes (145 nm, 353 nm, and 101 μm) and a relative density greater than 93.83% were irradiated with 4 MeV Xe ions at a fluence of 2 × 1015 ions/cm2 at room temperature, followed by annealing at 600 °C for 3 h. Microstructure, including dislocation loops and bubble morphology of the irradiated samples, has been characterized. The average size of dislocation loops increases with increasing grain size. Large-sized dislocation loops are absent near the grain boundary because the boundary absorbs surrounding defects and prevents the dislocation loops from coalescing and expanding. The distribution of bubbles within the grain is uniform, whereas the large-sized and irregularly shaped xenon bubbles observed in the small grain exhibit pipe diffusion along the grain boundaries. The bubble diameter in the large-grained pellet is the smallest. As the grain size increases, the volumetric swelling of the irradiated pellets decreases while the areal density of Xe bubbles increases. Elemental segregation, which tends to occur at dislocation loops and grain boundaries, has been analyzed. Large-grained CeO2 pellet with lower-density grain boundaries exhibits better resistance to volumetric swelling and elemental segregation, suggesting that large-grained UO2 pellets could serve as a potential ATF. [ABSTRACT FROM AUTHOR]

In this research, the energy potential of switchgrass (SG) was analyzed to find promising directions for producing bioenergy from this biomass. The first direction is determining the thermal energy of bioethanol extracted from SG biomass after its pretreatment, enzymatic hydrolysis (saccharification), and fermentation of the resulting glucose. It was established that after a two-stage pretreatment of 1 ton of SG with dilute solutions of nitric acid and alkali, the largest amount of bioethanol can be extracted with an energy potential of 4.9 GJ. It is also shown that by the utilization of solid and liquid waste, the production cost of bioethanol can be reduced. On the other hand, the direct combustion of 1 ton of the initial SG biomass used as a solid biofuel provides an increased amount of thermal energy of 18.3 GJ, which is 3.7 times higher than the energy potential of the resulting bioethanol extracted from 1 ton of this biomass. Thus, if the ultimate goal is to obtain the maximum energy amount, then another direction for obtaining bioenergy from biomass should be implemented, namely, direct combustion, preferably after pelletizing. Studies have shown that fuel characteristics of SG pellets such as the gross thermal energy and density of thermal energy are lower than those of wood pellets, but they can be improved if the SG biomass is densified into pellets together with binders made from polymer waste. [ABSTRACT FROM AUTHOR]

We recorded the diet of Amur Falcons (Falco amurensis) during their autumn passage at stopover sites across in Northeast India. We collected and examined 1200 pellets to identify prey remains in the diet of Amur Falcons from three major stopover sites in Nagaland State in the years 2017 and 2018. Additionally, in 2019, we examined 200 pellets each at two other sites in the neighboring states of Assam and Manipur. We only recorded insect prey belonging to five taxonomic orders: Orthoptera, Isoptera, Hemiptera, Coleoptera, and Hymenoptera, with Isoptera being dominant in the diet of Amur Falcons. The frequency of occurrence of Isoptera (termites) was the highest (87%) across years and across all stopover sites in Nagaland; diets were similar at the two other sites in Assam and Manipur. We identified the species of termites in the diet of Amur Falcons as Odontotermes feae and O. horni, the mass emergence of which coincided with the falcons' arrival in the region. We further estimated that 1,000,000 Amur Falcons stopping over for an average of 15 d in the region consumed approximately 67–134 metric tons of alates (approximately 1 to 2 billion individual alates). We concluded that Amur Falcons stop over in Northeast India primarily to refuel. Our study highlights the importance of availability of abundant termite prey for the success of Amur Falcons' onward migration, which includes oceanic crossings en route to Africa. [ABSTRACT FROM AUTHOR]

This study investigated self-heating and off-gassing of Scots pine (Pinus sylvestris) wood pellets made from sawdust generated from separated mature and juvenile wood. The pellets were produced at an industrial scale and stored in large piles of about 7.2 tonnes. The production process involved drying the sawdust using three different methods and to varying moisture contents. The results indicated significant influences of both raw material type (F(6) = 61.97, p < 0.05) and drying method (F(2) = 65.38, p < 0.05) on the self-heating of the pellets. The results from the multiple regression analysis further showed that both the raw material type and pellet moisture content significantly influenced the temperature increase, with strong correlations observed for pellets produced using low-temperature drying (F(3, 14) = 83.52, multiple R2 = 0.95, p < 0.05), and medium temperature drying (F(3, 13) = 62.05, multiple R2 = 0.93, p < 0.05). The pellets produced from fresh mature wood sawdust were found to be more prone to self-heating and off-gassing while steam drying the sawdust at high temperature and pressure led to a significant reduction in heat and gas generation across all materials. The heightened self-heating and off-gassing in mature wood pellet can be attributed to a higher proportion of sapwood in the raw material. The probable explanations to the observed differences are in line with biological mechanisms for self-heating and off-gassing, as well as the chemical oxidation of fatty and resin acids. [ABSTRACT FROM AUTHOR]

Scientific studies on the impact of wood species on solid fuel production, performance, and sustainability are grossly inadequate. The knowledge of this is imperative as users of solid fuels are increasing rapidly, especially in Africa. On this note, it becomes necessary to explore measures that will improve its efficiency and sustainability as an energy source. This study investigates some properties of selected wood species used as an energy source in Nigeria and their pelleting potential. Nine samples were characterized and assessed for suitability of pelleting following four wood pellet quality standards. The properties investigated are physical (moisture content and density) and thermochemical (calorific value, ash content, volatile matter, fixed carbon, and ultimate properties (carbon, nitrogen, hydrogen, oxygen, sulfur, arsenic, cadmium, and lead)). These were selected because they are among the most important pellet parameters contained in the quality standards. The findings revealed a net calorific value between 10.61 MJ.kg−1 for Tectona grandis and 18.44 MJ.kg−1 for Eucalyptus cam. The ash content, volatile matter, and fixed carbon contents of the samples range between 2.1 and 24.4%, 65.94 and 87.77%, and 3.51 and 18.63%, respectively. Anogeissus leiocarpus was found to be the species with the best rating score in terms of fuel properties, while Vitellaria paradoxa was the lowest. However, in terms of conformity with the four wood pellet standards, Khaya senegalensis, Parkia biglobosa, and Eucalyptus cam., having presented density, calorific value, sulfur, arsenic, cadmium, and lead within the limits of the wood pellet quality standards, were considered the best wood species in terms of fuel suitability and pelleting potential. The findings therefore suggest that not all wood species are suitable as fuel. Thus, for species that do not meet the standard wood pellet requirements, alternatives such as the use of biomass blends, additives, or process adjustments can be employed to adapt the quality to the standards or by using the fuels in improved cookstoves. [ABSTRACT FROM AUTHOR]

Wood pellets on the German pellet market mainly consist of spruce wood, but other wood species are increasingly used during pellet production. Moreover, additives such as starch or kaolin can be added to improve fuel quality and combustion behavior. Consequently, wood pellets vary in their physical and chemical properties and this variation might affect combustion behavior in stoves and boilers. In this study, eight different wood species were used for pellet production at the Technology and Support Centre (TFZ). Three types of starch and one type of kaolin were added to spruce wood without bark, using two additivation levels (starch: 0.5 w-% and 1.8 w-%, kaolin: 0.17 and 0.34 w-%). All pellet assortments were analyzed according to international standards for solid biofuels and additional methods. Fuels were combusted in a 6-kW pellet stove and a 15-kW pellet boiler. Selection of wood species had a significant impact on CO emissions for the pellet stove ranging between 85 and 4189 mg/m3 and on TPM emissions ranging between 23 and 263 mg/m3. Similar combustion behavior was observed for the pellet boiler but on a lower emission level. Kaolin reduced CO and TPM emissions as well as slag formation when the additivation level was set according to stoichiometric calculations. When kaolin was overdosed, it had a negative impact on TPM emissions mainly in the pellet boiler, probably due to entrainment. Regarding particles from incomplete combustion, a negative impact of overdosed kaolin was observed. Overall, at the current state of the art, the pellet stove showed larger sensitivity towards variable pellet qualities compared to the automatic pellet boiler. This calls for further improvements in fuel design and stove technology. [ABSTRACT FROM AUTHOR]

Fully ceramic microencapsulated (FCM) fuel is a five-layer intercalation system material consisting of a UO2 core, a sparse pyrolytic carbon layer (Buffer), an inner dense pyrolytic carbon layer (IPyC), an outer dense pyrolytic carbon layer (OPyC), and a silicon carbide matrix (SiC). At first, this paper researched the thermodynamic models of the materials, including heat conduction coefficient, Young's modulus, thermal expansion coefficient, etc. Then DIGIMAT, the finite element software, was used to establish the equivalent volume element (RVE) for the equivalent analysis of the thermodynamic properties of the FCM fuel pellet. Finally, the thermodynamic equivalent performance model of FCM fuel was obtained by multi-factor fitting analysis. The results show that among these thermodynamic properties of FCM fuel pellets, the Young's modulus, thermal expansion coefficient and plastic performance are mainly affected by temperature, fast neutron fluence, and UO2 volume fraction; the specific heat capacity is mainly affected by UO2 volume fraction and temperature; the heat conduction coefficient is mainly affected by temperature and UO2 volume fraction. The thermal conductivity is mainly affected by temperature, burnup and UO2 volume fraction. In this study, the equivalent models obtained through the fitting analysis of RVE model parameters can well describe the thermodynamic behavior of FCM fuel particles. [ABSTRACT FROM AUTHOR]

This paper presents the findings of a study of the pelleting process of pine sawdust with the addition of waste in the form of potato pulp (as a natural binder), in the context of producing fuel pellets. The process of pelleting was carried out for sawdust and for a mixture of sawdust and potato pulp (10, 15, 20, and 25%). The highest moisture content was obtained in the case of pellets produced from a mixture of straw with a 25% potato pulp content, i.e., 26.54% (with a potato pulp moisture content of 85.08%). Increasing the potato pulp content in a mixture with sawdust from 10 to 25% reduced the power demand of the pelletizer by approx. 20% (from 7.35 to 5.92 kW). The obtained density values for pellets made from a mixture of sawdust and potato pulp (over 1000 kg∙m−3) with a potato pulp content of 10% make it possible to conclude that the obtained pellets meet the requirements of the ISO 17225-2:2021-11 standard. Increasing the potato pulp content from 0 to 25% caused a slight decrease in the heat of combustion, i.e., from 20.45 to 20.32 MJ∙kg−1, as well as in the calorific value, from 19.02 to 18.83 MJ∙kg−1 (both for dry sawdust matter and the mixture). The results of the laboratory tests were used to verify the densification process of mixtures of sawdust and potato pulp under industrial conditions at the PANBAH plant, using pelleting mixtures with a 5%, 10%, and 25% content of potato pulp. Industrial research also confirmed that the use of the addition of potato pulp in a mixture with sawdust significantly reduces the power demand of the pelletizer, and it also increases the kinetic strength of the obtained pellets. [ABSTRACT FROM AUTHOR]

This article compares the emission of gaseous pollutants such as CO2, CO, NO, SO2, and HCl emissions from the combustion of the selected most popular solid fuels in a low-power boiler. The process was carried out under controlled conditions on a laboratory stand equipped with a Moderator Unica Vento Eko 25 kW boiler. Solid fuels were selected for comparison, such as hard coal with granulation above 60 mm, hard coal with a granulation of 25–80 mm, hard coal with a granulation of 8–25 mm, wood pellets, and mixed firewood. The experiment was carried out in two stages. In stage 1, previously selected solid fuels were combusted under controlled repeatable conditions, while simultaneously measuring gaseous components in the exhaust gases in real time. On the other hand, the second stage involves the combustion of the same fuels under the same conditions with combustion additives that modify the combustion process in terms of reducing the emission of pollutants. At the same time, in the second stage, gaseous components in the exhaust gas were also measured in real time. The experiments carried out have shown that, in addition to the additive, a testing system should be used to assess the profitability and improve the efficiency of energy production and distribution after using a given additive for fuel combustion. Implementation of the use of solid fuel activators on a common scale should also entail research on the emission of dioxins and furans, which may be emitted in increased amounts under the influence of some components contained in combustion modifiers. [ABSTRACT FROM AUTHOR]

This study proposed a strategy to prepare metalized pellets for direct steelmaking by hydrogen cooling reduction (HCR) of iron ore pellets with a focus on the effect of H2 flow rate on the process. It was demonstrated that increasing H2 flow rate could effectively enhance the reduction performance of iron ore pellets. However, due to the influence of the countercurrent diffusion resistance of gas molecules, too high H2 flow rate no longer promoted the reduction of the pellets when the maximum reduction rate was reached. The reduction swelling index (RSI) of the pellets initially increased and then decreased with increasing H2 flow rate. This change was associated with the decreased content of Fe2SiO4 in the metalized pellets and the changes in porosity and iron particle size. The compressive strength (CS) decreased continuously, showing a sharp decline when the H2 flow rate reached 0.6 L/min. It was attributed to the significant increases in porosity and average pore size of the metalized pellets, with the presence of surface cracks. When the H2 flow rate was 0.8 L/min, the metalized pellets had the optimal performance, namely, reduction degree of 91.45%, metallization degree of 84.07%, total iron content of 80.67 wt%, RSI of 4.66%, and CS of 1265 N/p. The findings demonstrated the importance of controlling the H2 flow rate in the preparation of metallized pellets by HCR. [ABSTRACT FROM AUTHOR]

Loose powder in metal hydride reactors poses challenges, such as poor thermal conductivity and tube deformation. To address these issues, the metal powder can be encapsulated in a polymer-based matrix to form pellets. This encapsulation helps make the pellets oxygen-impermeable, capable of accommodating the volumetric expansion of metal hydrides, and increases system processability. This study investigates the use of polymer-based pellets containing AB5-based compounds for ambient hydrogen storage. Polymers were selected using ANSYS Granta software, and polyethylene and polymethylmethacrylate were chosen. The AB5 alloy activation in the pellet occurs efficiently after 3 min at 20 °C and 30 bar of hydrogen, facilitated by ball milling-induced reactive surfaces and increased grain boundaries. The optimized pellet, comprising 90 wt% AB5 powder in a PE matrix, exhibits stable hydrogen storage properties, with good mechanical resistance and minimal powder loss (below 3%) over 20 hydrogen sorption cycles in an in-house fabricated single-tube metal hydride reactor. [Display omitted] • Loose metal hydride powder bound in a polymer matrix formed pellets without solvents, simplifying handling and processing. • PE and PMMA were selected via ANSYS Granta as suitable matrix materials for hydride pellets, ensuring effective binding. • 90 wt.% AB5 in a PE matrix demonstrated stable H₂ storage, strong mechanical properties, and less than 3% powder loss. • AB5 alloy in the pellets activated within 3 min at 20°C and 30 bar H₂, enabling rapid and efficient hydrogen storage. • Pellets maintained consistent performance through 20 hydrogen sorption cycles in a custom single-tube reactor. [ABSTRACT FROM AUTHOR]

The by-products of the wine industry represent a global production of 10.5 to 13.1 million tons of wine pomace annually. This study examines the chemical composition and energy potential of wine pomace and distillation stillage, evaluating their suitability for pellet production within ENplus® standards. Proximate analysis, elemental analysis, and calorimetric analysis were conducted on samples of the two by-products collected in a local Distillery in Portugal. The results reveal that wine pomace has a higher volatile matter content (62.695%) than distillation stillage, which, however, has lower ash content (3.762%) and higher fixed carbon (31.813%). Calorimetric analyses show that distillation stillage has a superior low heating value compared to wine pomace, with values exceeding 19 MJ/kg. Both by-products, however, exceed ENplus® limits for ash (≤0.70), nitrogen (≤0.3), and sulfur (≤0.04) content, presenting challenges for use as high-quality fuel pellets. Combining these biomasses with other materials could reduce the pollutant content of the pellet and improve efficiency. This study highlights the need for pre-treatment strategies to lower ash content and enhance combustion. Policy support for sustainable practices is essential to optimize the use of wine pomace and distillation stillage as renewable energy sources. [ABSTRACT FROM AUTHOR]

This study evaluated the suitability of two types of beech wood pellets as renewable, low-emission biofuel sources in order to combat the energy mix and poor air quality in Serbia. Key solid biofuel characteristics, including the heating values (18.5–18.7 MJ/kg), moisture content (5.54–7.16%), and volatile matter (82.4–84.4%) were assessed according to established standards. The elemental composition (mass fractions of 48.26–48.53% carbon, 6% hydrogen, 0.12–0.2% nitrogen, 0.02% sulfur, non-detected chlorine) and ash content (0.46–1.2%) demonstrated that the analyzed beech pellets met the criteria for high-quality classification, aligning with the ENplus A1 and ENplus A2 standards. The emissions of O2, CO2, CO, NOx, SO2, and TOC were quantified in the flue gas of an automatic residential pellet stove and compared with the existing literature. While combustion of the beech pellets yielded low emissions of SO2 (6 mg/m3) and NOx (188 mg/m3), the fluctuating CO (1456–2064 mg/m3) and TOC (26.75–61.46 mg/m3) levels were influenced by the appliance performance. These findings underscore the potential of beech wood pellets as a premium solid biofuel option for Serbian households, offering implications for both end-users and policymakers. [ABSTRACT FROM AUTHOR]

From 2010 to 2020, the main counties (cities and districts) with fruit forest pruning and fruit cultivation (citrus, pomegranate, apple, pear and grapes) were studied as the research objects, based on the fruit forest pruning coefficient and the discount coal coefficient, the pruning resources of fruit forests in Yunnan Province were estimated, the biomass fuel potential was estimated, and the temporal and spatial distribution characteristics were analyzed. The results showed that from 2010 to 2020, the total amount of pruning resources in fruit forests in Yunnan Province showed an upward trend, and the average annual pruning amount of shoots was 1,522,700 tons. The resources of fruit forest pruning were significantly different between different regions. In 2020, the resources of fruit forest pruning in Yunnan Province were 2,617,500 tons, including 6 counties with more than 100,000 tons, 8 counties with 50,000 tons to 100,000 tons, and 31 counties with less than 50,000 tons. The annual average amount of shoots converted into pellet fuel into standard coal was 918,000 tons, and the average annual amount of standard coal converted into natural gas and power generation was 690 million m³ and 7 472 million kWh, respectively, and the potential annual value generated was 4 184 million yuan. Yunnan Province has great potential for energy conversion of fruit forest pruning branches, excellent resource endowment conditions for the development of biomass fuel, and has the resource base for the industrialization of biomass pellet fuel. [ABSTRACT FROM AUTHOR]

In the present research, metal hydride pellets were synthesized to enhance the kinetics of hydrogen charge/discharge processes. By incorporating ENG (expanded natural graphite) and copper additives, we observed improvements in the heat transfer coefficients and storage capacities of the hydrogen storage materials. The reactor is designed to contain 1000 g of storage material in the form of powder or 25 pellets each weighing 40 g. The influence of storage materials with enhanced thermal conductivity on the hydrogen charge/discharge process was experimentally studied in a metal hydride reactor under a pressure of 10 bar. The reactor was heated under vacuum (10−4 mmHg) to approximately 200 °C for 2 h in order to complete the activation process. Following the heating process, the reactor was allowed to cool to ambient temperature, after which the hydrogen was introduced to the reactor at 10 bar pressure for 50 min. The absorption and desorption procedure was reiterated up to 20 cycles, and recordings of data were taken at intervals of 5 cycles to monitor the variations between the cycles. After 10 charge/discharge cycles under pressure of 10 bar, the hydrogen stored in the reactor amounted to approximately 9.93 g in pellet form and 7.20 g in powder form. • Hydrogen charging time is shortened with ENG additive and copper coating. • Hydrogen absorption/desorption cycle performances in the reactor were investigated. • For full activation, the heating and cooling process was repeated 5, 10, 15, 20 times. • It has been observed that the amount of hydrogen storage in pellet form increases. [ABSTRACT FROM AUTHOR]

Microstructure and Cr2O3 doping profoundly impact the thermal-mechanical properties and fracture of oxides fuels. It is a challenge to study the transient behavior of nuclear fuels under loss-of-coolant-event (LOCA). In this study, the crack behavior of UO2 pellets with controlled grain structure and Cr2O3 doping was tested with rapid power ramping (300−900 °C per min) mimicking a prototypical LOCA heating profile. Dense micron-sized UO2 pellets display well-maintained integrity without cracking with the ramping up to 1500 °C at a heating rate of 8 °C per second. Fracture occurs in both pure and Cr2O3-doped dense nano-sized UO2 pellets. The Cr2O3 doped oxide fuel pellet with a larger grain size (~ 22.2 μm) displays the best performance under LOCA testing due to its highest thermal conductivity under high temperature. FEA calculations suggest a temperature gradient across the fuel pellet during transient testing, resulting in residual stress and cracking, which can be correlated with their thermal-mechanical properties. [ABSTRACT FROM AUTHOR]

Although the principal physical behaviour of a material is inherently connected to its fundamental crystal structure, the behaviours observed in the real-world are often driven by the microstructure, which for many polycrystalline materials, equates to the size and shape of the constituent crystal grains. Here we highlight a cutting edge synthesis route to the controlled engineering of grain structures in thin films and the simplification of associated 3-dimensional problems to less complex 2D ones. This has been applied to the actinide ceramic, uranium dioxide, to replicate structures typical in nuclear fission fuel pellets, in order to investigate the oxidation and subsequent transformation of cubic UO2 to orthorhombic U3O8. This article shows how this synthesis approach could be utilised to investigate a range of phenomena, affected by grain morphology, and highlights some unusual results in the oxidation behaviour of UO2, regarding the phase transition to U3O8. [ABSTRACT FROM AUTHOR]

This article examines the effects of different storage conditions on selected physicochemical properties of three types of agro-biomass pellets: sunflower husks, wheat straw and hemp hurds, and wood pellets. The tests were carried out in a climatic chamber, which allows simulation of real storage conditions, i.e. conditions with high air humidity and variable (±) ambient air temperatures. The results showed higher degradability of agro-biomass pellets compared to woody biomass. The pellets degraded to a less extent at varying ± temperatures than at high humidity (90% RH). After complete moisture saturation, durability decreases for agro-pellets by an average of 9%, while after freezing and defreezing for sunflower husk pellets and woody pellets durability decreases by 2%, and for hemp hurd pellets by 11%. In contrast, strength-by-dropping index for agro-pellets decreased by 20% after being in the environment (30 °C and 90%RH) and 15% under varying temperature conditions. No change in the energy parameters of all pellets in the dry matter was noted. On the other hand, an increase in the moisture content of pellets when they are stored under different environmental conditions results in a decrease in calorific value. [ABSTRACT FROM AUTHOR]

The arc furnace is an important equipment in the production of manganese ferroalloys. In the smelting process, it produces high temperature flue gas above 700 K, which has high utilization value. During the pelleting process, moisture exists on the surface and inside of the pellets, which, if directly fed into the arc furnace, will lower the temperature of the furnace, affecting the production, and will also cause the pellets to burst, resulting in pressure fluctuations in the furnace and other hazards. The preheating shaft kiln reduces the moisture content of the pellet while preheating the pellet by utilizing high temperature flue gas. In this paper, through the establishment of porous media and shrinking core coupling mathematical model, to achieve the prediction of the heating and drying process of the pellets of various particle sizes, which is in good agreement with the production monitoring data. The results show that 9~11 mm pellets have the best preheating effect in terms of tail gas temperature, pellet temperature and preheating time. [ABSTRACT FROM AUTHOR]

Biomass, due to its neutrality in terms of greenhouse gas emissions into the atmosphere during its life cycle, is considered an interesting renewable source for energy production as an alternative to the use of more polluting fossil fuels. Among the different wood fuels, pellets are convenient for use in dedicated stoves, and pellet heating systems have a high energy efficiency. The aim of this work was to estimate the economic and global warming potential (GWP100a) generated along the thermal energy supply chain of wood pellets, starting from the production of raw biomass from dedicated poplar cultivations and ending with the use of pellets in stoves by the end-user to produce thermal energy and ash. The Eco-Efficiency Indicator (EEI) was used to link the economic and environmental performance for eight proposed scenarios, obtained by combining different levels of mechanisation for poplar harvesting and wood biomass management before arrival at the pellet plant. For the thermal energy produced by the poplar wood pellet, the GWP100a ranged from 1.5 × 10−2 to 2.1 × 10−2 kg CO2−eq MJ−1 for three-year-old plantations and from 1.9 × 10−2 to 2.4 × 10−2 kg CO2−eq MJ−1, for six-year-old plantations. In terms of eco-efficiency of the baseline scenario (EEIb), the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIb values ranging from 0.31 to 0.60 € kgCO2−eq−1, compared to from 0.29 to 0.36 € kgCO2−eq−1 for pellets obtained from biomass produced from six-year-old poplar plantations. In terms of the Global Eco-Efficiency Indicator (EEIg), which also takes into account the positive effect on the reduction of greenhouse gases due to the storage of carbon in the soil by the plantations and the reduction of emissions from avoided fossil fuels, the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIg values that vary in the range of 0.60 ÷ 1.04 € kgCO2−eq−1, compared to 0.55 ÷ 0.62 € kg CO2−eq−1 for thermal energy obtained using biomass from six-year-old poplar plantations. [ABSTRACT FROM AUTHOR]

This paper includes a discussion of the results of tests concerning changes in the thermal and emission parameters of a boiler fuelled with wood biomass under the influence of air gradation in the combustion process. The test results ensure insight into the combustion process of wood biomass with air gradation, which significantly affected the operation of the device, increasing the mass concentration of the emitted nitrogen oxide (NOx) by combustion temperature lowering, especially in the afterburning zone. The authors observed an increase in the emission of particulate matter (PM) and carbon monoxide (CO) related to the change in the combustion process stoichiometry. The tests were carried out with the use of a heating boiler equipped with an automatic pellet burner. Apart from the mass concentration measurement of the pollution emitted, the tests focused on the measurements of temperature and oxygen levels in the flue gas. The objective of the tests was to confirm the applicability of the air gradation techniques in biomass combustion in order to reduce the emission of harmful substances from heating boilers, which is a technique that has recently been used in this group of devices. The test results obtained confirm the necessity for reorganising the technical systems of the currently used pellet burners and implementing further empirical tests. [ABSTRACT FROM AUTHOR]

The use of agroforestry biomass provides several advantages, both from an environmental point of view, in terms of the mitigation of global warming, and in terms of a circular economy for agricultural or agroforestry companies that reuse pruning residues as a source of energy. However, even if the use of energy pellets resulting from the pruning residues of various agroforestry species has excellent potential for the valorization of agricultural by-products, the physicochemical characteristics of these pellets have been scarcely studied by the scientific community. In this context, this study aims to assess the valorization potential of various lignocellulosic material residues produced during agroforestry activities. The objectives of the study include evaluating the chemical and physical characteristics of pellets produced with different mixtures of agroforestry biomass (olive, citrus, black locust, poplar, paulownia, etc.) in order to determine the optimal pellet blend from an energy and physicochemical perspective. The results of this study demonstrate that this comprehensive analysis provides valuable information on the optimization of biomass mixtures for better energy valorization, addressing both compositional and combustion-related challenges. In fact, it is observed that the addition of citrus and olive biomass to the various mixtures increases their energy potential. Furthermore, all of the pellets analyzed are found to possess an adequate and useful durability index (PDI) for their handling during storage and transport operations. This study demonstrates that olive and citrus pruning residues can be used to improve biomasses that have poor suitability in energetic, physical, and chemical terms. Further studies could be useful to understand which specific interaction mechanisms have an influence on emissions in order to optimize mixtures using different biomass sources for sustainable energy production. [ABSTRACT FROM AUTHOR]

In this study, a series of suction-control oedometer tests were conducted on unsaturated and saturated MX80 bentonite pellet/powder mixtures. The mixture samples were imposed with various suctions from 0 to 113 MPa under a low vertical stress (0.1 MPa). Then, the mixture samples were loaded in steps with controlled suction until reaching three different target stresses σv (0.1, 3.2, and 12.8 MPa) and instantaneously unloaded. The microstructure of unloaded samples was observed with mercury intrusion porosimetry (MIP) and microcomputed tomography (μCT), together with the determination of suction, water content, void ratio, and saturation degree. Results showed that the water-retention behavior of bentonite pellet/powder mixture was rather characterized by pellets instead of powder. Due to the stress release, the measured suction after unloading sme was larger than the imposed suction sim. The suction difference Δs between sme and sim depended on both suction and load. Under a given σv , the suction effect was characterized by an increase of Δs when sim decreased from 113 to 4.2 MPa, but by a noticeable decrease of Δs when sim further decreased to zero. This was found to be related to the changes of the slopes of soil-water retention curves (SWRCs): the slope was decreasing with suction increases after 4.2 MPa suction, but was increasing with suction increases before 4.2 MPa suction. As far as the stress effect was concerned, a larger Δs was identified at a higher σv for a given sim. The narrowing difference between Δs and the reduction of mean stress of pellet Δppellet with increasing load was because of the decrease of larger pores due to loading. The total mixture void ratio eTmixture was highly dependent on suction and vertical stress, whereas the total pellet void ratio eTpellet was only dependent on suction in the stress range considered. [ABSTRACT FROM AUTHOR]

We developed a Zr two-photon resonance ionization scheme with a high useful yield of 6.3(5)%. This scheme utilizes the known intermediate energy level at 26443.88 cm−1 and a newly characterized Rydberg level at 53490.79(26) cm−1. Both the first (378.16 nm) and second (369.727 nm) transition wavelengths are accessible by frequency-doubled titanium:Sapphire lasers. We utilize the new scheme to analyze the isotopics of Zr, a fission product, in micrometer-sized spent nuclear fuel samples to understand their irradiation history. This includes the dependence on burnup and radial location within a fuel pellet. Resonance ionization mass spectrometry was used to obtain almost isobar-free Zr isotopic ratios from seven samples. The measured isotopic ratios from the spent nuclear fuel show a strong dependence on radial position within the fuel pellet while the effect of average pellet burnup was much less pronounced. All Zr isotopic ratios systematically change from the pellet center to the pellet edge, where isotopic values are close to those expected from 235U fission and 239Pu fission, respectively. Using Zr isotopics, we demonstrate a potential method to distinguish between samples derived from the edge or center of a fuel element of unknown pedigree, which strongly impacts the interpretation of a sample's irradiation history as the neutron fields are different between these locations. [ABSTRACT FROM AUTHOR]

Forest fires and logging drive the structure of boreal forest landscapes. According to recent studies, stand origin is a key driver of the variation in wood properties in black spruce (Picea mariana (Mill.) BSP.), although the underlying mechanisms remain to be elucidated. By comparing post-cut, post-fire and old-growth forests, this study aimed to better distinguish the effects of stand structure from those of the seed or layer origin of the trees on wood properties. We conducted comparative analyses based on ecological characteristics of the sites and static bending tests of small, defect-free wood specimens. Black spruce stands with a regular structure established after logging or fire exhibited higher stiffness at a given cambial age than old-growth forests with irregular structures, as well as lower wood density in the first 40 rings near the pith. However, the bending strength was comparable in all three types of forests studied. Differences in wood stiffness among stand types appeared to be driven more by stand structure than by the seed or layer origin of the stems. [ABSTRACT FROM AUTHOR]

The coke deposition on catalysts is a significant problem in the dry reforming of methane at elevated pressures. Understanding and controlling the mechanisms of such deposition is essential in developing a techno‐economically viable industrial application for the production of synthesis gas and/or hydrogen. The patent‐pending nickel‐supported upgraded slag oxide (Ni‐UGSO) catalysts, in powder form, have demonstrated excellent performance and achieved equilibrium in dry reforming, steam reforming and mixed methane reforming in a gram‐scale laboratory packed bed reactor under barometric pressure. In this extended study, Ni‐UGSO pellets were prepared using the wet impregnation method. The pelletized form of said catalyst was studied under elevated pressure to imitate the industrial operating conditions in a kilogram‐scale laboratory packed bed reactor. The characterization of the fresh and used catalytic formulation produced data allowing the investigation of the physicochemical properties of catalysts and the effects of metal dispersion, reaction pressure and crystallite size, as well as the role of side reactions on the nature of the coke. The metal support nature favored the interaction between the Ni metal and spinels (UGSO), and the presence of the clay binder (kaolinite, quartz) improved the pellet morphology, provided higher Ni dispersion, maintained the crystallite size, reduced the coke formation and achieved similar or higher performance with respect to Ni‐UGSO powder despite having 85% less surface area. The Ni‐UGSO pellet showed negligible coke deposits from 1 to 6.5 atm and operated successfully for 24 h at 5.5 atm, 800°C and gas hourly space velocity 810 L/(h kg cat). This study provides new insight into the design of a more efficient and robust catalyst for methane dry reforming at elevated pressures, which is critical for potential future transfer at the industrial level. [ABSTRACT FROM AUTHOR]

Coffee consumption is a daily habit for the majority of people worldwide, resulting in consistently large amounts of residue. Spent coffee ground (SCG) is the residue obtained during the brewing process. It represents an abundant source of energy biomass, or raw material for added value products but it is still largely unexploited. This residue may find several applications, such as in polymers/composites precursors, solid/liquid biofuels, biofertilizers, and so forth. The aim of the present paper was the pilot production of pellets by mixing SCG and other residual biomass feedstock. Coffee residues were mixed at different ratios (0, 10, 30, 50, 70, 90 wt%) together with: (i) forestry residues; (ii) sawmill residues; (iii) urban prunings; (iv) maize residues; (v) peach prunings; and (vi) miscanthus. Samples of each fuel mixture were analyzed at the Solid Fuels Laboratory of CPERI/CERTH (Chemical Process and Energy Resources Institute/Centre for Research and Technology Hellas) in Greece by applying established standards. The results of the analyses show that the mixing of biomass residues with coffee could result in competitive solid biofuels. More specifically, pellets with up to 10% coffee residues, mixed with sawmill residues, complied with the class A2 limits set by the international standard ISO 17225‐2 for wood pellets, and pellets with up to 30% coffee residues complied with the class B limits for wood pellets for commercial/residential applications. Urban prunings mixed with 10 wt% coffee residues are within the limits set for class B wood pellets. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The production of silage using fish viscera can be carried out with straightforward methods and permits the exploitation of nutrients that are usually discarded. This process fosters the concept of circular aquaculture. The aim of this study was to evaluate the inclusion of increasing levels of fish viscera silage (VS) on the physical quality of the feed pellets and their effects on their growth performance, health parameters and on economic indices when the experimental extruded feed was offered to tambaqui. A fermented fish VS produced in‐house was included in increasing levels on a wet‐basis in the formulation of five experimental diets (VS 0%, VS 5%; VS 10%; VS 15% and VS 20%). Juvenile tambaqui (~22.6 g) were stocked in fibreglass tanks of 700 L (n = 4; 21 fish per tank) with a recirculation system and the five experimental diets were attributed in a completely randomized design. The fish were fed with the experimental diets (to apparent satiation) for 13 weeks. At the end of the trial, no significant differences were observed for production performance. Fish fed with the highest inclusion level of VS presented the highest concentration of plasma cholesterol, but this was still within acceptable values for this species. The inclusion of fish VS in diets for juvenile tambaqui reduced the activity of the plasma ALT enzyme, confirming normal liver function. Extruded feed containing fish VS had a production cost of US$ 0.95 per kg, which does not significantly impact the economic indices. Up to 20% of fish VS can be included in the extruded feed formulation for juvenile tambaqui without impairing growth performance or affecting health parameters. [ABSTRACT FROM AUTHOR]

• Electrical resistivity tomography, a new approach for detecting smouldering fires. • A region of R / R o ≥ 50 % corresponds to smouldering hotspots. • Increase in resistivity at smouldering hotspots is attributed to drop in moisture. • ERT can work well for material having moisture content as high as 50%. • ERT technology can be applied for silos and pile storage of organic material. Incidents of waste and biofuel fires are common at all stages of the waste recycling chain and have grave implications for business, employees, firefighters, society, and environment. An early detection of waste and biofuel fires in the smouldering stage could save precious lives, resources, and our environment. Existing fire detection methodologies e.g. handheld temperature sensors, IR cameras, gas sensors, and video and satellite-based monitoring techniques have inherent limitations to efficiently detect smouldering fires. An attempt was made to explore the potential of electrical resistivity tomography (ERT) as an alternate tool to address the problem. In the experiments an externally powered resistive wire was employed to initiate the smouldering fire inside the test material (wood pellets, wood shavings, wood fines). Time series of ERT that followed the initiation and development of smouldering were recorded using an automated monitoring instrument setup. The actual geometry of the experimental sample container and electrode setup was integrated in the 3D finite element method (FEM) model grid to perform inverse numerical modelling (inversion) and to develop resistivity tomographic images. The study shows a sharp increase in ratio of resistivity (R / R o ≥ 50 %) in the test material in the region of smouldering hotspot and demonstrates the potential use of ERT technique for the detection of smouldering hotspots in silos and pile storage of organic material such as wood-based fuels, wood waste, coal, municipal solid waste (MSW), recyclables etc. More research is however required for enabling the use of this technique at the practical scale for different storage conditions. [ABSTRACT FROM AUTHOR]

The aim of this study was to conduct a comprehensive economic and energy efficiency analysis of selected digestate management methods, considering their implications on operational costs and resource management. To achieve this aim, the study focuses on a comparative assessment of different digestate management methods, including land application, mechanical separation, the composting process and pellet production. The economic analysis involves the evaluation of the initial investment, operational expenses, and potential revenue streams associated with each method. The most economical and popular solution of digestate management is direct use as fertilizer, with total costs of 1.98 EUR·Mg−1. All of the other methods involve higher digestate management costs, respectively; for separation it is 2.42 EUR·Mg−1, for composting it is 2.81 EUR·Mg−1. The process that is the most energy-intensive, but profitable, is the production of pellets from digestate, resulting in profits of 334,926 EUR·year−1. It should be noted that the other analyzed methods of digestate management also bring many environmental benefits, affecting sustainability and reducing emissions. The results of this research will contribute unique data on the feasibility of managing the digestate and its fractions. The calculations of economic and energy values for different strategies will allow for the optimization of the overall performance of the biogas plant, thus promoting a circular economy. [ABSTRACT FROM AUTHOR]

Experimental measurements and modeling have been performed in the chimney of a biomass boiler to study the gaseous and particulate matter (PM) emissions during the combustion of wood pellets. A 10 kW boiler with an underfeed burner is equipped with different sensors located in the chimney (anemometer, thermocouples). The PM emissions were measured in the chimney through the engine exhaust particle sizer (EEPS) technique. Moreover, the gaseous emissions (CO2, CO, total hydrocarbons THC, O2) were obtained through infrared (IR) spectroscopy and flame ionization detector (FID). The emissions were recorded during the steady phase of the boiler and averaged over several tests. Four locations were investigated in the chimney to evaluate the evolution of the particle size and the potential deposition on the surface. The experimental results were compared with a CFD model with particle transportation. The modeling of turbulent flow in the chimney is based on a Reynolds-averaged Navier–Stokes (RANS) approach with turbulent viscosity closure. To account for flow anisotropy, the v 2 ¯ − f turbulence model was selected for this study. The effect of turbulent fluctuations on the discrete phase is considered by the discrete random walk (DRW) turbulent dispersion model. The results obtained provide access to the topology of the carrier phase flow as well as the complete distribution of the particle field within the chimney enclosure. Advanced measurement of pollutant emissions and modeling of the PM transportation are developed for the first time in a domestic biomass boiler operating in real conditions. Experimental results demonstrate several relevant information. The CO and THC emissions show a similar evolution versus time. The PM granulometric distribution measured along the chimney highlights the particle agglomeration phenomena. Moreover, the CFD model and experimental results give similar results in terms of flow characteristics and PM granulometry. [ABSTRACT FROM AUTHOR]

Wood pellet is an important biomass-based source of cleaner and renewable energy with a growing global demand. Populus spp. (poplars) are fast-growing trees with high productivity potential in the southeastern US. Selected pellet-quality parameters were examined as a proxy for assessing if the feedstock quality of poplar stem wood was affected by stand location (Coastal, Piedmont, Mountains of North Carolina, clone "140"), stand age (five vs. seven years, clone-"140"), clones ("140", "176", "230", "185", "356") and stem sections (clone-"356") by examining sulfur, ash, volatile-matter, fixed-carbon, gross caloric, carbon, hydrogen, and nitrogen contents of moisture-free samples. Location-study samples significantly varied (p≤0.027) in ash (0.6–0.9 wt%), and gross caloric (19.75–19.89 MJ/kg) contents and study clones significantly differed (p≤0.0271) in ash (means: 0.75–0.97 wt%), volatile-matter (means: 80.5–82.7 wt%), fixed-carbon (means: 16.5–18.7 wt%) and hydrogen (means: 4.19–4.78 wt%) contents. The only other significant variations were hydrogen (mean: 4.19–4.67 wt%) content with stand age (p≤0.009) and gross caloric values (19.5–19.9 MJ/kg) among stem sections (p = 0.0003). This study showed that poplars have stem-wood quality suitable for pellet production and most of the studied feedstock samples had ash, nitrogen, sulfur, and caloric (at 10% moisture content) contents that would meet the ENplus pellet-quality standards. Results from this study can be used for facilitating decisions about managing poplar stands for sustainable pellet feedstock production in the southeastern US, including selecting optimum rotation length, pellet-suitable clones, and sites. [ABSTRACT FROM AUTHOR]

The drying process is a crucial stage in the thermal treatment of iron ore pellets in a straight grate, as it has a direct impact on pellet quality and energy consumption. Consequently, this paper develops a simulation model for the pellet bed drying process, which is validated through industrial data and enables the visualization of temperature and moisture distribution within the pellet bed. Based on the simulation model, an optimization model for the drying process is developed to minimize the specific energy consumption per tonne of green pellets. The constraints of the drying process are the moisture content requirements and burst temperature. A genetic algorithm is employed to optimize the parameters such as trolley speed, pellet bed thickness, air temperature, and air pressure. The results show that, with an absolute error criterion of 10 °C, the temperature calculation accuracy of the simulation model exceeds 86%, effectively describing the drying process in a straight grate sintering machine. Under yield limitations, the optimal cumulative energy consumption per tonne of green pellet is reduced by 1.50% during the drying process. Finally, a simulation and optimization system for the drying process in the straight grate is implemented in C++. This system not only generates essential data for designing the drying section in a straight grate but also lays a theoretical foundation for system optimization and optimal control. [ABSTRACT FROM AUTHOR]

The Energy Return On Investment (EROI) is a recognised indicator for assessing the relevance of an energy project in terms of net energy delivered to society. For woody biomass divergences remain on the right methodology to assess the EROI leading to large variations in the published estimates. This article presents an in‐depth discussion about the EROI of woody biomass in three different forms: woodchips, pellets and liquid fuels. The conceptualisation of EROI is further developed to reach a consistent definition for biomass post‐processed fuels. It considers, on top of the external energy investments, the grey energy associated with the energy used to enrich the fuel. With the proposed methodology, all woodchips have an EROI of the same order of magnitude, between 20 and 37, depending on forestry types, operations and machineries. For secondary residues, the first estimate is 170 if, as co‐products, no energy investment is allocated to the forestry operations and transport. On the basis of a mass allocation for forestry operations and transport, the EROI for secondary residues becomes of the same order of magnitude as that for wood chips. Woodchips can be further post‐processed into pellets or liquid fuels. Pellets have an EROI of 4–7 if the heat is externally supplied and 8–23 if internally supplied (self‐consumption of part of the raw material). Liquid fuels derived from primary wood and residues through gasification and Fischer‐Tropsch synthesis have an EROI between 4 and 16. Fuel enhancement with hydrogen (Power & Biomass to Liquids) impacts negatively the EROI due to the low EROI of hydrogen produced from renewable electricity. However, these fuels offer other advantages such as improved carbon efficiency. A correct estimate of EROI for forestry biomass, as proposed in this work, is a necessary dimension in assessing the suitability of a project. [ABSTRACT FROM AUTHOR]

In this study, a novel fluidized-bed homogeneous granulation (FBHo-G) process was developed to recover lithium (Li) from industrial Li-impacted wastewater. Five important operational variables (i.e., temperatures, pH, [P]0/[Li]0 molar ratios, surface loadings, and up-flow velocities (Umf)) were selected to optimize the Li recovery (TR%) and granulation ratio (GR%) efficiencies of the process. The optimal operational conditions were determined as the following: a temperature of 75 °C, pH of 11.5, [P]0/[Li]0 of 0.5, surface loading of 2.5 kg/m2·h, and Umf of 35.7 m/h). The TR% and GR% at optimal condition could be as much as 90%. The material characterization of the recovery pellet products showed that they were highly crystallized Li3PO4 (purity ~88.2%). The pellets had a round shape and smooth surface with an average size of 0.65 mm, so could easily be stored and transported. The high purity enables them to be further directly reused as raw materials for a wide range of industrial applications (e.g., in the synthesis of cathode materials). Our calculation shows that the FBHo-G process could recover up to 0.1845 kg of lithium per cubic meter of Li-containing wastewater, at a recovery rate of ~90%. A brief technoeconomic analysis shows that FBHG process had economic viability, with an estimate production cost of USD 26/kg Li removed, while the potential gained profit for selling lithium phosphate pellets could be up to USD 48 per the same volume of wastewater and the net profit up to USD 22/m3 Li treated. In all, fluidized-bed homogeneous granulation, a seedless one-step recovery process, opens a promising pathway toward a green and sustainable recycling industry for the recovery and application of the resource-limited lithium element from nonconventional water sources. [ABSTRACT FROM AUTHOR]

This paper presents the results of analysing the energy performance improvement of the final commercial prototype (FCP), based on the monitoring results discussed in the previous paper regarding the commercial prototype (CP). Similar to the previous paper, the energy balance (EB) was carried out according to the regulation no. 245 established by the Romanian Agency for Energy Conservation (RAEC). The monitoring system was the one used previously. The mathematical model used for the optimised energy balance (OEB) of the FCP is also presented. We carried out the OEB of the FCP for a few different operating conditions, of which we present two, differing also by the type of fuel: corn grains and wood pellets (70% beech and 30% fir) respectively. The FCP monitoring process was carried out again after improving its thermal insulation, by infrared thermal vision. The experimental results were used as input for the mathematical model, and the results are presented in the conclusions. [ABSTRACT FROM AUTHOR]

Concept drift describes unforeseeable changes in the underlying distribution of streaming data over time. Concept drift is a phenomenon in which the statistical properties of a target domain change over time in an arbitrary way. These changes might be caused by changes in hidden variables that cannot be measured directly. With the onset of the big data era, domains such as social networks, meteorology, and finance are generating copious amounts of streaming data. Embedded within these data, the issue of concept drift can affect the attributes of streaming data in various ways, leading to a decline in the accuracy and performance of models. There is a pressing need for new models to re-adapt to the changes in streaming data. Traditional concept drift detection algorithms struggle to effectively capture and utilize the key feature points of concept drift within complex time series, thereby failing to maintain the accuracy and efficiency of the models. In light of these challenges, this study introduces a novel concept drift detection method that incorporates a temporal attention mechanism within a prototypical network. By integrating a temporal attention mechanism during the feature extraction process, our approach enhances the capability to process complex time series data, preserves temporal locality, strengthens the learning of key features, and reduces the amount of labeled data required. This method significantly improves the detection accuracy and efficiency of small sample streaming data by better capturing the local features of the data. Experiments conducted across multiple datasets demonstrate that this method exhibits comprehensive leading performance in terms of accuracy and F1-score, with excellent recall and precision, thereby validating its effectiveness in enhancing concept drift detection in streaming data. [ABSTRACT FROM AUTHOR]

Perennial nectar‐producing wild plant species (WPS) cultivation for biogas production helps improve ecosystem services such as habitat functioning, erosion mitigation, groundwater protection, and carbon sequestration. These ecosystem services could be improved when WPS are harvested in late winter to produce pellets and briquettes as solid energy carriers for heat production. This study aims for gaining first insights into the use of WPS biomass as resource for pellet and briquette combustion with focus on two perennial WPS common tansy (Tanacetum vulgare L.) and mugwort (Artemisia vulgaris L.), and two biennial WPS yellow melilot (Melilotus officinalis L.) and wild teasel (Dipsacus fullonum L.). All WPS are found economically viable for pellet combustion. The main drivers are i) low cultivation costs, ii) subsidies, and iii) low pellet production costs due to low moisture contents. However, high ash contents in WPS biomass justify the need of i) blending with woody‐biomass or ii) supplementing with additives to attain international standards for household stoves. This approach appears technically feasible providing a research field with significant potential impacts. As 70% of the pellet market is demanded as household level, public concern about the legal framework of alternative plant biomass pellets must be overcome to develop this market. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) serves as extensively researched adsorbents, with numerous established methods for their preparation. This study originated from the hypothesis that compressing a hydrocarbon substance to create a densely compacted pellet, known as pelletizing, would enhance the development of porous features of the resulting AC. The anticipated enhancement is attributed to the rise in spatial proximity amidst HEC polymer chains within the bulk of the pellet, which facilitates aromatization both in extent and functionality. 2-Hydroxyethyl cellulose (HEC) pellets were prepared by adjusting the duration of load holding, aiming to increase the packing density of HEC polymer chains via creeping. The BET analysis of the resulting AC samples demonstrates the efficacy of compression on HEC pellets in enhancing their porous properties. The FE-SEM study revealed diverse AC surface morphologies that are associated with a set of specific pelletizing conditions. The 13C NMR spectroscopy for carbon skeletons, FT-IR spectroscopy for organic functionality, and XPS spectroscopy for surface composition collectively report the leverage of compression treatment before pyrolyzing HEC pellets. Furthermore, the assessment of hydrogen sulfide adsorption by the resulting AC samples revealed distinctive breakthrough curves, providing validation for the proposed compression effect. [ABSTRACT FROM AUTHOR]

Understanding how the size of fuel particles influences the initiation and spread of smoldering fronts is an important consideration in the spread of wildfires. Natural fuels often consist of layers of organic materials of varying sizes, yet the influence of the size of the particle on the burning behavior is not well understood. Changes in the size of particles can influence how readily oxygen transports to the reaction zone, how particles heat and burn, and how much heat transfers between particles. With this background, the objective of this study was to identify sensitivities of smoldering behavior to the size of particles and elucidate changes in heat transfer and oxygen transport in causing observed sensitivities. To achieve this objective, experiments were conducted where fuel beds of granulated Douglas-fir wood pellets of varying particle sizes were put in contact with an ignition source. The propensity to sustain horizontal and downward smoldering combustion and the resulting propagation rates and temperatures were quantified. Tests of homogenous and mixed particle sizes were investigated. In general, particle sizes with characteristic diameters (d) > 1.27 mm did not transition to self-sustained smoldering, while particle sizes with d < 1.27 mm transitioned to self-sustained smoldering, irrespective of the ignition temperature. Increasing the size of particles reduced the spread rate and surface temperature, despite having lower overall densities. Larger particles could sustain smoldering if sufficient concentrations of smaller particles were present in the pores. Fuel beds with increased porosity and permeability (i.e., larger particles) had reduced propensity to sustain smoldering showing that how readily oxygen can be transported to the reaction zone is not a limiting condition for particles of this size when burns are near the surface. A simplified heat transfer analysis was conducted to consider the contributions of conduction, convection, and radiation in transferring heat between particles. Increasing particle size decreases the heat transfer rate between particles as a result of greater heat loss due to convection. Additionally, smaller particles have similar Biot numbers resulting in increased heating rate, ignitability and spread rates. The results from this work provide insights into the important influences that the size of the fuel particles can play in smoldering near surfaces (i.e., up to 8 cm evaluated). [ABSTRACT FROM AUTHOR]

Woody biomass energy has exponentially grown in the last decade as a renewable energy alternative to fossil fuels. The growing trend of burning trees amid global climate crisis suggests that the wood pellet industry has been grossly successful in positioning itself as a sustainability leader. What communicative frames and strategies has the industry harnessed to communicate sustainability? What do the frames and strategies leave out? To explore those questions, this paper examines the woody biomass industry's construction of sustainability by focusing on the case of the world's largest wood pellet company, Enviva. Following ecolinguistics and framing theory, the first part of the paper examines the company's website and social media presence to unpack the frames that Enviva engages to communicate its sustainability. Then, the paper turns to the spheres of life that the company omits from its framing but are crucial to the conceptualization of sustainability from an ecojustice perspective. The paper concludes with a call for ecojustice as the framework for evaluating sustainability of life on land. [ABSTRACT FROM AUTHOR]

Improving energy content and hydrophobic nature of woody biomass can be pursued through torrefaction. This gives torrefied biomass with a low bulk density, potentially increasing storage and transport costs. To overcome this issue, densifying the torrefied biomass is necessary. However, poor binding of particles makes densification challenging without using a binder. Therefore, the aim of this study was to investigate the physicochemical characteristics and techno-economic aspects of torrefied rubberwood biomass (TRWB) when pelletized using various cassava-based binders at different blending ratios. The selected binders included cassava starch (CS), cassava pulp (CP), and cassava chip (CC). Each binder at 5%, 10%, or 15% (wt.) was mixed with TRWB and water before pelletizing using a flat die machine. The results revealed that pelletizing TRWB with different cassava-based binders at various blending ratios influenced the physicochemical characteristics of the TRWB pellets, particularly dimensions, bulk density, fuel and atomic ratios, and energy content. The TRWB pellets demonstrated energy densities in the range of 7.95–11.39 GJ/m3, and their mechanical durability and fine content fell within acceptable ranges. The TRWB pellets maintained their shape during 120 min of water soaking, with water absorption levels varying by binder dose. The pelletizing ability, material, and energy costs of TRWB pellets depend on binder type and dose. CP can be applied as a binder for pelletizing torrefied rubberwood biomass. However, the mechanical durability of the product needs to be above the user requirement or standard. [ABSTRACT FROM AUTHOR]

This study evaluates the quality of 30 biomass pellets sold for residential use in Poland. It provides data on their physical, chemical, and petrographic properties and compares them to existing standards and the information provided by the fuel producers. The results reveal considerable variations in the quality of the pellets and show that some of the purchased samples are not within the DINplus and/or ENplus certification thresholds. Among all 30 purchased samples, only one passes the quality thresholds set by the PL-US BIO, a newly established quality certification in Poland that combines quality assessment following DINplus with optical microscopy analysis. The primary issues causing a decrease in pellet quality include elevated ash and fines content, compromised mechanical durability, too low ash melting temperature, and additions of undesired additions like bark, inorganic matter, and petroleum products. Our research highlights the need for improved fuel quality control measures, and transparent and accurate product labeling, as well as the need for a comprehensive and publicly available national database of solid biomass fuel producers and fuels sold. These are essential steps toward increasing customers' awareness and trust, encouraging them to embrace biomass fuels as reliable and sustainable sources of energy. [ABSTRACT FROM AUTHOR]

This paper presents the results of the rearing of European catfish (Silurus glanis l.) larvae in a flow-through production system using three feeding schemes - Variant A was control and consisted of dry pellet food; Variant B - dry pellet food and supplement of frozen Chironomus, Variant C - dry pellet food and supplement of frozen Artemia. Each of the experimental variants was applied in 2 tanks with the same stocking density - 15 ex/l-1 at 40 l maintained volume. The growth performance of the larvae in the three experimental variants was compared in terms of final biomass (FB), individual weight gain (IWG), total weight gain (TWG), specific growth rate (SGR), daily growth rate (DGR), feed conversion ratio (FCR) and survival rate (SR). The highest final biomass was reported in Variant B with nutritional supplement of Chironomus, with significant difference when compared to Variant A and Variant C (P≤0.05). The daily growth rate was the highest in Variant B and the lowest in Variant C (P ≤ 0.05). The specific growth rate confirmed the daily rate values and was again the highest in Variant B and lowest in Variant C (P ≤ 0.01). The highest survival rate was achieved in Variant B, with a difference of 15.93% with Variant C (P ≤ 0.05). Based on the results of the fish production parameters it can be concluded that the most effective nutritional option, for rearing S. glanis larvae, was Variant B with supplement of frozen Chironomus. [ABSTRACT FROM AUTHOR]