Search Results (23)

Background: Returning pineapple leaves (PAL), banana stems (BAS), coconut husks (CCH), and organic fertilizer (OF) to the field is an important method for soil improvement. However, the effects of these materials on the soil remain unclear. Methods: This study employed a nylon-bag experiment filled with the above-mentioned materials to investigate the impacts on soil physicochemical properties and microbial community structure. Results: The short term acidification caused by PAL was due to the significant increase in isobutyric, isovaleric, and hexanoic acids. PAL and BAS promoted the formation of >0.25 mm aggregates in the short term (90 days). C and N were most abundant in <0.053 mm and 0.053–0.25 mm soil aggregates, while ¹³C and ¹⁵N were mainly enriched in 0.25–2 mm and >2 mm soil aggregates. The dominant biomarkers in the soil treated with PAL were Koribacteraceae, Chrysozymaceae, Trimorphomycetaceae, and Tremellales. The main biomarkers of soil treated with BAS were Caulobacteraceae, Aspergillaceae, Onygenales, and Ceratostomataceae. The dominant biomakers in the soil treated with CCH and OF were richer than those in soil treated with PAL and BAS. Conclusions: The long term return effects of CCH and OF are better than those of PAL and BAS. Full article

Due to the soft mechanical properties of soft rock strata, roof fall accidents are frequent, causing great hazards to production. In order to eliminate hazards in the actual mining process, a new type of bag-filling scheme was designed by analyzing the mechanisms of roof falls in soft rock strata. By testing the filling material, the optimal ratio of foam filling material was determined, and the corresponding filling process was formulated. Through the field verification of this filling process, better support was achieved in the roof fall area, providing useful guidance and support for mines with similar conditions. Full article

Salt marshes are vital coastal ecosystems, increasingly threatened by rising sea level and human pressures, that provide essential services, including coastal protection, habitat support, and carbon sequestration. This study examines the effectiveness of different eco-engineering structures in restoring salt marshes in the Mondego Estuary, Portugal, by assessing their impacts on benthic macroinvertebrate communities as bioindicators of ecosystem health. The experimental design included five experimental cells: wood palisade (Fence), geotextile fabric (Geotextile), geotextile bags filled with sand (Bags), a cell with autochthonous vegetation (Plants), and a Control cell with bare soil. Monitoring took place from 2019 to 2021, with both before and after intervention sampling to evaluate species composition, biomass, and density. Key ecological indices, such as the AZTI’s Marine Biotic Index (AMBI), Shannon-Wiener Diversity, and Pielou’s Evenness, were calculated alongside measurements of environmental variables. The results indicated minimal impacts on biodiversity, with observed variations primarily attributed to seasonal dynamics. While the wood palisade enhanced species richness and density, geotextile provided better community stability. The findings emphasize the importance of long-term monitoring, stakeholder engagement, and sustainable use of materials to optimize restoration efforts and better inform coastal management strategies in the face of climate change. Full article

The packed-bed bioreactor is among the most promising reactor configurations for solid-state fermentation. However, the bed thickness poses several limitations involving mass and energy transfer, heat generation, and the homogeneity of the material, hampering its development at the industrial scale. Fungi are among the most promising microorganisms used in this configuration; however, only polypropylene bags and trays are used at the industrial scale. In this work, Beauveria bassiana is used to demonstrate the potential of solid-state fermentation for conidia production. A scale-up from 0.5 L to 22 L is presented, starting with substrate selection, optimization via design of experiments and 22 L batches. The optimized parameters were 70% moisture, 6.5 × 10⁶ conidia mL⁻¹ inoculum concentration, 20 mL min⁻¹ airflow, 25 °C; temperature, and 40 C/N ratio. After optimization, beer draff was chosen as the preferred substrate for scale-up. Air-filled porosity was found to be the key parameter in fungal solid-state fermentation scale-up, establishing values of around 80% as necessary for fungal conidia production when working in a 22 L packed-bed bioreactor. When compared with the tray bioreactor, the packed bed obtained higher conidia production due to its better use of the total reactor volume. Our study harnesses the potential of the packed-bed bioreactor and serves as a base for further scale-up to industrial scale. Full article

Crop residue decomposition is fundamental for ecosystems, influencing carbon cycling, organic matter accumulation, and promoting plant development through nutrient release. Therefore, this study aimed to ascertain the rate of decomposition of four commonly cultivated crops (alfalfa, maize, avocado, and eucalyptus) along the northern coast of Lima (Huaral) and in the Ancash Mountain range (Jangas) areas. Decomposition rates were assessed using mass loss from decomposition bags measuring 15 × 10 cm, filled with 10–15 g of material tailored to each species, and buried at a depth of approximately 5 cm. Sampling occurred every three months over a year, totaling four sampling events with three replicates each, resulting in ninety-six experimental units. The findings demonstrate that the decomposition rates and the release of nutrients were markedly greater in Huaral for maize and avocado. In contrast, these rates were notably elevated in Jangas for alfalfa and eucalyptus. The leaf litter of avocado and eucalyptus (tree) had periods of accumulation and release of heavy metals such as Cd. The initial C/N ratio was one of the main factors related to the nutrient decomposition rate; in contrast, there were no significant relationships with soil properties at the study sites. Full article

As damming material, fine-grained tailings present challenges such as low dam strength and poor stability. To address these issues, this study employs geotextile tube technology to mix water with fine-grained tailings, forming a tailing slurry with a concentration of 60%, which is filled into a geotextile bag to form a geotextile tube, so as to improve the stability of fine-grained tailings. The shear strength characteristics of each interface under different consolidation times and different filling degrees were studied via an indoor shear experiment, including the shear strength of tailing particles, that between tailings and geotextiles, and that within geotextile tubes themselves. The results show that the shear strength of each interface conforms to the Mohr–Coulomb strength criterion, and that the interface cohesion is greatly affected by the consolidation time, while the interface friction angle is mainly affected by the filling degree. Moreover, the shear strength comparison, based on the comprehensive friction angle concept, indicates a substantial increase in shear strength at the interfaces between geotextile tubes compared to both that of the tailings themselves and the interface between tailings and geotextiles, highlighting the reinforcing effect of the geotextile tube filling technology on tailings’ shear strength. Full article

The problem of the growing amount of waste polymer materials currently affects virtually every area of the global economy. New actions taken by the E.U. and member states could lead to a reduction in the burden on the natural environment, as well as the reuse of thermoplastic waste. The aim of this study was to analyze the possibility of reusing post-industrial waste (recycled polypropylene—rPP) in order to produce mixtures with original polypropylene (PP) and glass fibers. The research undertaken is characterized by a high level of innovation and was carried out on an industrial scale from industrial waste. The primary goal of the analyses was to determine changes in the properties of the polymer mixtures depending on the amount of recycled polymers. For this purpose, four types of mixtures were prepared, characterized by different degrees of filling with recycled material obtained from big-bag packaging (the filling levels were 0 wt.%, 20 wt.%, 30 wt.%, and 70 wt.%). A detailed analysis of the physical properties of the obtained mixtures was carried out to determine changes in the densities depending on the amount of rPP material. In addition, changes in the MFIs (melt flow indexes), characterizing viscosity changes, were analyzed depending on the amount of secondary raw material used. An analysis of the mechanical properties was also carried out based on static tensile testing, the impact strength (the Charpy method), and the Rockwell hardness test (the M method). The analysis of the thermal changes was performed using the DSC method. The results showed that the composites made of virgin polypropylene (PP GF30) and those made from re-granulates and glass fibers (rPP GF30) are characterized by similar mechanical properties and significantly different processing properties, determined by MFI. This means that the addition of re-granulates significantly affects the processability of the obtained materials, while the addition of glass fibers maintains the basic mechanical properties. Full article

A pressure filtration–flocculation–solidification combined treatment possesses great potential for the reutilization of the waste mud slurry generated from diverse construction projects as filling material due to its versatility and high efficiency. However, very limited existing studies have focused on the factors affecting pressure filtration’s efficiency. In this paper, a calculation model for compression filtration is established based on laboratory pressure filtration model tests and one-dimensional large-strain consolidation theory. The influence of various parameters on pressure filtration’s efficiency is analyzed, and favorable values for these parameters are recommended. The results show that an increased initial mud cake thickness significantly increases the dewatering time and reduces the treatment’s efficiency. A lower dewatering time and higher efficiency can be achieved by increasing the filtration pressure, but the efficiency improvements become limited after reaching the critical pressure threshold. For the mud slurry used in this study, the optimal values for the initial mud slurry bag thickness, filtration pressure, and dewatering time are 240 mm, 1.0 MPa, and 30 min, respectively, yielding a final mud cake water content of 58.7% after filtration. Full article

Soilbags are expandable three-dimensional geosynthetic bags made from high-density polyethylene or polypropylene. This study conducted a series of plate load tests to explore the bearing capacity of soft foundations reinforced by soilbags filled with solid wastes based on an onshore wind farm project in China. The effect of contained material on the bearing capacity of the soilbag-reinforced foundation was investigated during the field tests. The experimental studies indicated that soilbag reinforcement with reused solid wastes could substantially improve the bearing capacity of soft foundations under vertical loading conditions. Solid wastes like excavated soil or brick slag residues were found to be suitable as contained material, and the soilbags with plain soil mixed with brick slag had higher bearing capacity than those with pure plain soil. The earth pressure analysis indicated that stress diffusion occurred through the soilbag layers to reduce the load transferred to the underlying soft soil. The stress diffusion angle of soilbag reinforcement obtained from the tests was approximately 38°. In addition, combining soilbag reinforcement with bottom sludge permeable treatment was an effective foundation reinforcement method, which required fewer soilbag layers due to its relatively high permeability. Furthermore, soilbags are considered sustainable construction materials with advantages such as high construction efficiency, low cost, easy reclamation and environmental friendliness while making full use of local solid wastes. Full article

Plastic waste poses a significant challenge for the environment, particularly smaller plastic products that are often difficult to recycle or collect. In this study, we developed a fully biodegradable composite material from pineapple field waste that is suitable for small-sized plastic products that are difficult to recycle, such as bread clips. We utilized starch from waste pineapple stems, which is high in amylose content, as the matrix, and added glycerol and calcium carbonate as the plasticizer and filler, respectively, to improve the material’s moldability and hardness. We varied the amounts of glycerol (20–50% by weight) and calcium carbonate (0–30 wt.%) to produce composite samples with a wide range of mechanical properties. The tensile moduli were in the range of 45–1100 MPa, with tensile strengths of 2–17 MPa and an elongation at break of 10–50%. The resulting materials exhibited good water resistance and had lower water absorption (~30–60%) than other types of starch-based materials. Soil burial tests showed that the material completely disintegrated into particles smaller than 1 mm within 14 days. We also created a bread clip prototype to test the material’s ability to hold a filled bag tightly. The obtained results demonstrate the potential of using pineapple stem starch as a sustainable alternative to petroleum-based and biobased synthetic materials in small-sized plastic products while promoting a circular bioeconomy. Full article

Rapid and sensitive detection of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for early diagnosis and effective treatment. Nucleic acid testing has been considered the gold standard method for the diagnosis of COVID-19 for its high sensitivity and specificity. However, the polymerase chain reaction (PCR)-based method in the central lab requires expensive equipment and well-trained personnel, which makes it difficult to be used in resource-limited settings. It highlights the need for a sensitive and simple assay that allows potential patients to detect SARS-CoV-2 by themselves. Here, we developed an electricity-free self-testing system based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) that allows for rapid and accurate detection of SARS-CoV-2. Our system employs a heating bag as the heat source, and a 3D-printed box filled with phase change material (PCM) that successfully regulates the temperature for the RT-LAMP. The colorimetric method could be completed in 40 min and the results could be read out by the naked eye. A ratiometric measurement for exact readout was also incorporated to improve the detection accuracy of the system. This self-testing system is a promising tool for point-of-care testing (POCT) that enables rapid and sensitive diagnosis of SARS-CoV-2 in the real world and will improve the current COVID-19 screening efforts for control and mitigation of the pandemic. Full article

Face masks have become an essential commodity during the COVID-19 pandemic, and their use rises daily. Excessive face mask use will likely continue to combat the virus and bacterial impacts in the long term. Afterward, used face masks are hazardous to the environment since most are made of nonbiodegradable porous polymeric fibrous materials. Thus, finding new ways to recycle waste face masks is urgently needed. Similarly, managing agricultural water for irrigation is a crucial challenge in saving water. This study demonstrates an approach for recycling face masks as bag- or small-sized pillows filled with superabsorbent polymers (SAPs) for the slow release of water near plant roots. Previous studies have reported that SAPs or hydrogel could boost soil’s water retention capacity, mixed with hydrogel/SAP. However, mixing SAPs into soil is improper because biodegradation generates low toxic organic molecules and contaminates soil and surface water. The objective of this research was to develop a face mask reuse approach, reduce irrigation water using polymers, and reduce toxic contamination in the soil. Here, swollen SAPs were taken inside the pillow and buried near plants, and the growth of the plants was studied. The moisture of the inner soil was constant for a long time, boosting plant growth. Afterward, the face mask pillows could be removed from the soil and maintained for further use. This new approach could be helpful in pot farming. This approach could contribute to the circular economy and the development of environmental sustainability. Full article

Purpose: This paper presents an aspect of asset tracking and storage conditions. This paper aims to fill the gap in the development of Industry 4.0 in terms of fully digital asset tracking to be implemented by medium and large-size manufacturing and logistics facilities. The article presents an innovative technology for the remote monitoring of chemical raw materials, including fertilizers, during their storage and transport from the place of manufacture to the local distributor or recipient. Methods: The method assumes the monitoring and identification of special transport bags, so-called “big-bags,” through embedded RFID tags or LEB labels and monitoring the key parameters of their content, i.e., temperature, humidity, insolation, and pressure, using a measuring micro-station that is placed in the transported raw material. Results: The automation of inference based on the collected information about the phenomenon in question (the distribution of parameters: pressure, temperature, and humidity), and expert knowledge, allows the creation of an advisory system prototype indicating how to manage the measuring devices. Conclusions: No similar solution in the field of monitoring environmental parameters has been implemented in the Polish market. The developed system enables the monitoring of 10,000 pieces of big bags in at least 30 locations simultaneously. Full article

In this paper, shields made of 1.3964 stainless steel bonded to a fiber laminate were subjected to ballistic impact response of 7.62 × 51 mm ŁPS (light projectile with a lead core) projectiles. Additionally, between the steel sheet metal and the laminate, a liquid-filled bag was placed, which was a mixture of ethylene glycol (C₂H₆O₂) with 5 wt.% SiO₂ nanopowder. Numerical modeling of the projectile penetrating the samples was carried out using the finite element method in the Abaqus program. The elasto-plastic behavior of the projectile material and the component layers of the shields was taken into account. Projectile penetration through glycol-filled bag has been performed using the smooth particle hydrodynamics technique. The morphology of the penetration channel was also analyzed using a scanning electron microscope. For the shield variant with a glycol-filled bag between the steel and laminate plates, the inlet speed of projectile was 834 m/s on average, and 366 m/s behind the sample. For the variant where there was no glycol-filled bag between the steel and laminate plates, the inlet and outlet average velocities were 836 m/s, after 481 m/s, respectively. Referring to the steel-glycol-laminate and steel-laminate variants, it can be concluded that the laminate-glycol-laminate is more effective. Full article

Starch is a naturally occurring material showing high potential for use in food packaging because of its low cost, natural abundance and high biodegradability. Over the years, different starch-based packaging films have been developed, but the impact of botanical sources on film performance has rarely been exploited. Efforts devoted to exploiting the role played by the clusteroluminescence of starch in food packaging are also lacking. This study fills these gaps by comparing the properties of edible starch films generated from different botanical sources (including water chestnuts, maize and potatoes) in food packaging. Such films are produced by solution casting. They are highly homogeneous, with a thickness of 55–65 μm. Variations in the botanical sources of starch have no significant impact on the color parameters (including L*, a* and b*) and morphological features of the films but affect the water vapor permeability, maximum tensile strength and elongation at break. Starch films from water chestnut show the highest percentage of transmittance, whereas those from potatoes are the opaquest. No observable change in the intensity of clusteroluminescence occurs when a packaging bag generated from starch is used to package fresh or frozen chicken breast meat; however, a remarkable decline in the intensity of luminescence is noted when the frozen meat is thawed inside the bag. Our results reveal the impact of starch sources on the performance of starch films in food packaging and demonstrate the possibility of using the clusteroluminescence of starch as an indicator to reveal the state of packaged frozen food. Full article