Search Results (44)

Fermentation is a fundamental technique that allows us to obtain high-quality cacao beans and derived products. Therefore, it is necessary to apply fermentation correctly to maximize product quality. Fermentation techniques vary by region and include piles, trays, wooden boxes, baskets, and platforms. During these processes, several factors influence the physicochemical and sensory characteristics of cacao beans. The factors that influence these characteristics are the frequency of turning, the genotype of the bean, and the duration of fermentation. This review aims to explore how the fermentation method, turning frequency, bean genotype, and fermentation duration affect the physicochemical and sensory qualities of cacao beans. To this end, an exhaustive search for recent information on the most commonly used fermentation methods in cacao-producing countries over the last 10 years was carried out. The fermentation method in wooden boxes or crates is the most commonly used method worldwide. The most common turning frequency is 24 or 48 h, which is considered the most suitable time for obtaining cacao beans with better sensory attributes, such as floral and fruity aromas, and a lower level of acidity. Finally, a relationship was found between the genotype and the optimal fermentation time of cacao: about 4 days for Criollo cacao, approximately 5 days for Forastero cacao and between 1.5 and 10 days for Trinitario cacao. Full article

The global production of brewers’ spent grains (BSG) is 37 million tons yearly. Composting represents an eco-friendly method to manage and valorize organic by-products in a circular economy model. This project aims to compare two BSG bin-composting mixtures (BSG and wheat straw with pig slurry solid fraction, MIX1, or sheep manure, MIX2) and approaches (manual turning, MT, and static composting, ST). The two mixtures’ physicochemical characteristics and greenhouse gas (GHG) emissions were assessed during the process. The evolution of physicochemical properties is reported in detail. Headspace samples of GHG emissions were collected and analyzed with gas chromatography coupled with specific detectors. Carbon dioxide (CO₂) emissions were 34.3 ± 0.03 and 31.0 ± 0.06 g C kg⁻¹ fresh matter (FM) for MIX1-MT and MIX2-MT, and 28.8 ± 0.01 and 31.2 ± 0.02 g Ckg⁻¹ FM for MIX1-ST and MIX2-ST. Methane emissions were negligible (all conditions < 0.086 ± 0.00 mg C kg⁻¹ FM). Nitrous oxide (N₂O) emissions from composting are affected by the substrate, bulking material, pile dimension, and manure. Particularly, the total emissions of N₂O, estimated as CO₂ equivalents, were 45.8 ± 0.2 and 63.0 ± 0.4 g CO₂ eq kg⁻¹ FM for MIX1-MT and MIX1-ST, respectively. In both composting approaches, MIX2 showed a low CO₂ equivalent (1.8 ± 0.02 and 9.9 ± 0.05 g CO₂ eq kg⁻¹ FM for MT and ST), likely due to incomplete decomposition. The bin-composting process represents a solution for recycling and reusing organic waste and livestock manure in small to medium-sized breweries. The solid fraction of the pig slurry resulted in the most suitable manure. Full article

Aerobic composting is widely used for the degradation of organic matter, simultaneously reducing the presence of antibiotic resistance genes (ARGs) in swine manure. However, the phenomenon of abundance rebound or even enrichment of ARGs is still a problem. The effect and mechanism of humus soil (Hs) on ARG reduction by adding it into the piles (0% for the control group (CK); 10% for S1 group; 20% for S2 group; and 30% for S3 group) after the thermophilic phase of composting was investigated. The results indicated that Hs promoted organic matter degradation and nitrogen loss. During days 15–36, the greatest reduction of 69.91% in total ARG abundance was observed in S2, while the abundance rebounded by 222.75% in CK and decreased only 13.71% in S3. With the 20% Hs addition, 85.42% abundance reduction for mobile genetic elements (MGEs) and 100% removal rates for aadA5, aadA9, sul1, sul2, and tetX were achieved. Moreover, the addition of Hs immediately changed the bacterial community structure of the substrate and varied the bacterial community successional direction in the treatments. Additionally, significantly positive correlations (|r| > 0.6; p < 0.05) were found between the top 20 genera and ARGs. The potential host bacteria for ARGs changed from Lactobacillus, Fermentimonas, Pusillimonas, and Ruminofilibacter in CK to Lactobacillus, Romboutsia, and Streptococcus in S2, highlighting the shift and reduction in host bacteria driven by Hs, which, in turn, influenced the abundance variations in ARGs. This study verified the feasibility of inhibiting the rebound of ARG abundance effectively by influencing the microecological niche in the pile, offering an approach for promoting a reduction in ARGs in animal wastes. Full article

Cheese production generates a large amount of liquid waste called cheese whey (CW). The management of CW is not optimized in Ecuador since a large proportion of it is discharged into the soil or effluents, causing significant environmental impacts. For this reason, the co-composting of whey with solid organic wastes can be a suitable method for its treatment for small companies generating this liquid waste due to its effectiveness and low cost. In this study, we analyzed 10 CW samples from different small companies in the Mocha canton (Tungurahua, Ecuador) to determine specific physicochemical and chemical parameters. Subsequently, a waste pile was formed with crop residues (corn and beans) and cow manure, which was composted using the turned pile composting system. Throughout the composting process, the temperature of the pile was controlled, its moisture was maintained between 40 and 60% by adding whey, and several physicochemical, chemical, and biological properties were determined. The results showed that the CW presented a high organic load, notable macronutrient content, and low heavy metal concentrations, all of which are beneficial for its co-composting with other organic solid wastes. The only limiting factors involved in using large amounts of whey in the composting process were the low pH values of the acid CW and the high concentrations of salts. It was also observed that co-composting CW with agro-livestock wastes was a viable strategy to treat these wastes and produce compost with stabilized and humified organic matter and remarkable agricultural value. Full article

Humans may have evolved to be “hyperactive agency detectors”. Upon hearing a rustle in a pile of leaves, it would be safer to assume that an agent, like a lion, hides beneath (even if there may ultimately be nothing there). Can this evolutionary cognitive mechanism—and related mechanisms of anthropomorphism—explain some of people’s contemporary experience with using chatbots (e.g., ChatGPT, Gemini)? In this paper, we sketch how such mechanisms may engender the seemingly irresistible anthropomorphism of large language-based chatbots. We then explore the implications of this within the educational context. Specifically, we argue that people’s tendency to perceive a “mind in the machine” is a double-edged sword for educational progress: Though anthropomorphism can facilitate motivation and learning, it may also lead students to trust—and potentially over-trust—content generated by chatbots. To be sure, students do seem to recognize that LLM-generated content may, at times, be inaccurate. We argue, however, that the rise of anthropomorphism towards chatbots will only serve to further camouflage these inaccuracies. We close by considering how research can turn towards aiding students in becoming digitally literate—avoiding the pitfalls caused by perceiving agency and humanlike mental states in chatbots. Full article

This paper employs in situ Electron Backscatter Diffraction (EBSD) tensile technology to thoroughly consider the evolution of microstructure, grain size, grain boundary characteristics, orientation differences, and dislocation density of H13 steel during the elastic and plastic stages of room temperature tensile testing. The study unveils the deformation mechanisms of inclusions, carbides, and the matrix in H13 steel during the various stages, providing a comprehensive explanation for the slightly superior tensile properties of H13 steel when refined by Vacuum Induction Melting combined with Vacuum Arc Remelting (VIM + VAR) over those when refined by Electroslag Remelting (ESR). This discrepancy is primarily attributed to the differences in inclusions and carbides present in the two refining processes. The quantity and size of inclusions and carbides are closely related to material fracture. Large-sized carbides and inclusions were shown to be more likely to cause dislocation pile-ups and stress concentration. This, in turn, leads to faster crack initiation and propagation during plastic deformation. Conversely, the formation of micro-pores within these fine inclusions and the matrix is contingent on greater plastic deformation, resulting in a gradual and incremental linkage of these micro-pores to form dimples beneath the influence of slip. Full article

A significant concentration of pharmaceuticals has been detected within composted sewage sludge. Their uncomplete removal and lack of monitoring during composting neglects their potentially toxic effects when used as a soil organic amendment. Previously, we successfully implemented a bioaugmentation–composting system focused on toxicity and pharmaceuticals’ concentration reduction. This method, however, comprised a long inoculant-acclimatization period, making it an unprofitable technology. Hence, this work aimed to explore a shorter and yet effective composting process by simultaneously implementing the inoculation of a native microbial consortium and the fungus Penicillium oxalicum XD 3.1 in composting piles of sewage sludge and olive prunings. All the piles were subjected to frequent inoculation, windrow turning, and monitoring of the physicochemical and biological parameters. Additionally, both the bioaugmentation stability and pharmaceuticals degradation were evaluated through different analysis and removal rates calculations. One hundred days earlier than previous attempts, both bioaugmentation treatments achieved adequate composting conditions, maintained core native populations while improving the degrading microbial diversity, and achieved around 70–72% of pharmaceutical remotion. Nevertheless, only Penicillium inoculation produced favorable toxicity results ideal for organic amendments (acute microtoxicity and phytotoxicity). Thus, a shorter but equally stable and effective degrading bioaugmentation–composting with P. oxalicum was achieved here. Full article

Given integer n and k such that $0<k\le n$ and n piles of stones, two players alternate turns. On each move, a player is allowed to choose any k piles and remove exactly one stone from each. The player who has to move but cannot is the loser in the normal version of the game and (s)he is the winner in the misère version. Cases $k=1$ and $k=n$ are trivial. For $k=2$, the game was solved for $n\le 6$. For $n\le 4$, the Sprague–Grundy function was efficiently computed (for both versions). For $n=5,6$, a polynomial algorithm computing P-positions was obtained for the normal version. Then, for the case $k=n-1$, a very simple explicit rule that determines the Smith remoteness function was found for the normal version of the game: the player who has to move keeps a pile with the minimum even number of stones; if all piles have an odd number of stones, then (s)he keeps a maximum one, while the $n-1$ remaining piles are reduced by one stone each in accordance with the rules of the game. Computations show that the same rule works efficiently for the misère version too. The exceptions are sparse. We list some. Denote a position by $x=(x_1,\dots ,x_n)$. Due to symmetry, we can assume wlog that $x_1\le \dots \le x_n$. Our computations partition all exceptions into the following three families: $x_1$ is even, $x_1=1$, and odd $x_1\ge 3$. In all three cases, we suggest formulas covering all found exceptions, but it is not proven that there are no others. Full article

Composting is the decomposition of organic matter in an aerobic environment. The windrow turner machine is used to turn the compost piles for efficient composting. It effectively addresses important issues such as managing crop leftovers and disposing of animal waste. This paper evaluates a comparison between mechanized (pile 1) and conventional (pile 2) compost-turning processes and the need for windrow turner machines to manage waste effectively and turn it into nutrient-dense material. This approach not only delivers a practical solution, it also points out the potential for a significant increase in soil fertility and agricultural sustainability. Five samples were taken from each pile at 10 feet intervals for chemical analysis. A total 13,768 kg of the compost yield was collected from pile one and 11,512 kg from pile 2. The study’s findings show that the machine turned a greater cation exchange capacity (CEC) value than the compost manually turned. Pile 1 was turned using a compost windrow turner machine, and pile 2 was turned manually. The CEC values in pile 1 varied from 21.23 meq/100 g dry weight to 68.87 meq/100 g dry weight after eight weeks, while the CEC values in pile 2 increased from 21.23 meq/100 g dry weight to 33.28 meq/100 g dry weight. The value of electrical conductivity (EC) in pile 1 increased from 1.98 ds/m to 11.34 ds/m, whereas in pile 2 it climbed from 1.98 ds/m to 7.86 ds/m after 8 weeks. The C/N ratio of pile 1 dropped to approximately 15 and the concentration of micronutrients increased during the composting process, which indicate mature composted material. The outcomes of this research contribute that mechanical composting emerges as a highly suitable method for efficiently managing the composting process, ensuring uniform decomposition, enhanced aeration, and the production of high-quality compost. Full article

Optimizing open-end piles is crucial for sustainability as it minimizes material consumption and reduces environmental impact. By improving construction efficiency, less steel is needed, reducing the carbon footprint associated with production and transportation. Improved pile performance also results in more durable structures that require less frequent replacement and maintenance, which in turn saves resources and energy. This paper presents a parametric study on optimal designs for open-ended piles in sand, presenting a novel approach to directly compute optimal pile designs using CPT results. It addresses challenges posed by soil variability and layered conditions, with the optimization model accounting for interdependencies among pile length, diameter, wall thickness and soil properties, including the pile–soil plug system. A mixed-integer optimization model OPEN-Pile was developed, consisting of an objective function for pile mass and CO₂ emissions. The objective function was constrained by a set of design and geotechnical conditions that corresponded to current codes of practice and recommendations. The efficiency of the developed optimization model is illustrated by two case studies. In the case of Blessington sand, the calculation results show that it is more economical and environmentally friendly to increase the pile diameter and pile wall thickness than the pile length. In efficient design, the ratio between diameter and wall thickness is calculated at the upper limit. For the optimum design of piles in Blessington sand, the optimum ratios of pile length to diameter, diameter to wall thickness and length to wall thickness are 5, 50 and 250, respectively. In a layered soil profile, the decision of where to place the pile base depends on the resistance of the cone tip and the thickness of the individual layers. To determine in which layer the pile base should be placed, we need to perform an optimization for the given design data. Full article

Increasing production of municipal solid waste (MSW) drives the need for its disposal in a manner that is safe for the environment and human health. However, this may require short- or long-term storage before it can be properly processed. Similarly, a way of processing waste material is necessary for the re-cultivation of dump sites. This article presents the results of an investigation into the effects of long-term open-air storage upon waste material to be turned into refuse-derived fuel (RDF) by standard methods for the assessment of MSW and RDF pellet quality including bomb calorimetry, sieve analysis, furnace drying/burning for water/ash content assessment, and pellet expansion measurements. Results of the investigation indicate that such a form of storage bears no notable negative effect on the quality of the material; the pellet expansion coefficient, heat of combustion, and ash content were all found to be approximate to pre-storage values, with positive implications for the storage of solid waste and the prospects of its subsequent processing into solid fuel. It is shown that such material can be stored in open-air conditions for prolonged periods without the loss of desired parameters. In addition, a discussion of differences between the properties of material drawn from varying depths of the pile is provided and the potential impact of the findings in the context of the production and the storage of refuse-derived fuel is assessed. Full article

This paper develops an algorithm to compute optimal routes for an autonomous compost turner. In commercial composting, the material to be composted is piled up in large heaps called windrows and turned regularly by compost turners. The environment at the composting site is constantly changing, as the locations of the windrows change with each turning procedure. Therefore, we propose a novel method that automatically computes routes on a composting plant from LiDAR data. The LiDAR is mounted on the compost turner together with a dual-antenna GNSS receiver, an IMU, and rotary encoders. An extended Kalman filter is used to obtain the vehicle’s pose. Through direct georeferencing, a global point cloud is obtained. The routing algorithm crops, segments, and filters the point cloud until the points along the ridge of each windrow remain. These points are used to compute the optimal routes along each windrow. Furthermore, a user can select the windrows which need to be turned and the algorithm then computes the most efficient path for the compost turner, which also includes the passages between the windrows. The method was tested within a simulation environment using a 3D model of the composting site. The results show that the algorithm detects the windrows and computes the routes with sufficient accuracy for autonomous compost turning. Full article

The research area covers the border zone between the Central and Outer Carpathians. The purpose of this research was the interpretation of this zone based on a gravitational survey. This survey was integrated with the results of surface mapping, a deep seismic survey, and deep drillings. Three major tectonic units are located in this area: the Outer (Flysch) Carpathians, the Pieniny Klippen Belt (PKB), and the Central Carpathians. All three units contain a significant amount of flysch sequences. The lowering of the Bouguer anomaly value from north to south reflects the dip of the crystalline European Plate; in turn, the renewed increase in value correlates very well with the emergence of the crystalline ALCAPA Plate. The range of variability of the Bouguer anomaly value largely masks smaller anomalies in amplitude originating from smaller geological structures. Only three anomalies with significant horizontal extent and greater amplitudes are visible: two are clearly correlated with the Orava-Nowy Targ Basin and the third anomaly is likely connected with the thicker pile of the Outer Carpathian flysch. To separate the boundaries of geological or tectonic structures (lineaments), a horizontal derivative (THDR) and an analytical signal (ASA) were used. Both methods allowed us to confirm existing geological and tectonic boundaries (lineaments) and to identify new ones. Full article

The spatial effect at the end of the foundation pit partition wall is significant, and the displacement of the retaining wall and soil caused by its demolition leads to an additional displacement and bending moment of the adjacent pile foundations, which in turn deteriorates the work behavior of the pile foundation. Taking the project of an open tunnel under a viaduct located in Hangzhou as an example, site monitoring was performed to determine the effect of the demolition of the partition wall on the displacement of the surrounding retaining wall and the soil in the adjacent area and the monitoring data were compared to the finite element analysis results to check the rationality of the finite element model. This model was used to study the influence of the distance from the pile foundation to the partition wall as well as the stiffness of the retaining wall on the displacement and bending moment of the pile foundation during excavation. These results indicate that because of the support effect of the foundation pit partition wall on the retaining wall, the spatial effect at the end of the partition wall is large, and the displacement and bending moments of the pile foundation in the vicinity of the partition wall are lower than those in the far distance. Demolition of the partition wall will increase the displacement and bending moment of adjacent pile foundations, and this effect decreases with increasing distance. The range of influence of the spatial effect at the end of the partition wall is approximately 1.1 times the depth of the foundation pit. When the pile foundation is in the immediate vicinity of the partition wall, the response of the front-row and rear-row piles to the demolition of the partition wall is significantly different. The front row piles are more affected, while the rear row piles are less affected. As the distance increases, the difference in response gradually decreases and tends to be consistent. As the stiffness of the retaining wall increases, the effect of the demolition of the partition wall on the pile foundation decreases. It is recommended that the stiffness of the supporting system near the partition wall be reduced appropriately, and the partition wall should be set at the foundation pit section near the pile foundation, but the response of the foundation pit and the adjacent pile foundation should be paid close attention to when the partition wall is demolished. Full article

In recent years, there has been a rise in the construction of expansive underground structures and shield tunnels with exceptionally large diameters. These projects introduce unique challenges regarding their impact on the surrounding soil and structures, which differ from those typically encountered in conventional shield tunnels. However, the existing body of research in this specific domain remains insufficient. When such tunnels intersect deep foundation pits supported by piled-raft foundations, the discrepancies in soil deformation can become even more pronounced. At present, there is a dearth of research on the underlying principles governing these differences, and theoretical investigations have not kept pace with practical engineering applications. Consequently, the existing settlement prediction methods employed for diverse projects need to be reevaluated and adjusted to accommodate the distinctive characteristics of each individual project. Regarding the engineering focus of this paper, it is crucial to recognize that soil subsidence in the pit bottom has a significant influence on the mechanical response of the piles. Consequently, the implementation of targeted correction measures remains consistently important. Based on this concept, this paper focuses on a super-large diameter shield tunnel project that under-crossed a deep foundation pit with a piled-raft foundation. The influence of different construction methods on the settlement law of the soil at the bottom of the deep foundation pit is discussed after verification of the accuracy of the model through numerical simulation and field monitoring data. Additionally, two correction coefficients that consider the project’s load characteristics are proposed in this research. These coefficients were used to correct the surface settlement curve. The corrected soil settlement curve at the pit’s bottom can successfully reflect the numerical simulation results, which in turn can reflect the mechanical response of the pile under the influence of tunnel excavation. Full article