Search Results (429)

This study evaluated the effect of various adhesive systems, particularly silane application, on the repair bond strength of a nanofill resin composite and associated stress distribution using finite element analysis (FEA). A total of 105 composite specimens (4 × 6 mm) were aged by thermal cycling (10,000 cycles), roughened, etched with phosphoric acid, and assigned to seven groups (n = 15): G1. control—no adhesive; G2. Single Bond Universal Adhesive; G3. composite primer; G4. PQ1; G5. Silane + PQ1; G6. Clearfil Universal Bond; G7. All-Bond Universal. Shear bond strength was measured using a universal testing machine (1 mm/min), and failure modes were microscopically classified. FEA was conducted under static and fatigue conditions using 3D models built in Fusion-360. Mechanical properties were obtained from technical data and the literature. A 300 N load was applied and contact detection (0.05 mm) and constraint zones were defined. Statistical analysis was performed using one-way ANOVA and Tukey’s HSD (p = 0.05). Pearson’s correlation was used to assess the relationship between bond strength and von Mises stress. The highest bond strength was found in G2 (21.54 MPa) while G1 showed the lowest (8.86 MPa). Silane-treated groups exhibited favorable stress distribution and a strong correlation between experimental and simulated outcomes. Silane applications significantly enhance composite repair performance. Full article

Phosphorus deficiency poses a significant challenge to the growth and productivity of crops, particularly in nutrient-poor soils. This study investigates the effects of phosphorus deficiency on the growth, endogenous phytohormones, metabolome, and transcriptome of sweet potato (Ipomoea batatas L.) over a growth period from 30 to 120 days. We found that low phosphorus conditions significantly reduced both above- and below-ground biomass, while tuber number remained unchanged. Endogenous phytohormone analysis revealed altered levels of abscisic acid (ABA), indole-3-acetic acid (IAA), and cytokinins, indicating a complex hormonal response to phosphorus starvation. Transcriptomic analysis identified a total of 6324 differentially expressed genes (DEGs) at 60 days, with significant enrichment in pathways related to stress response and phosphorus utilization (PAPs and PHO1). Metabolomic profiling revealed notable shifts in key metabolites, with consistent downregulation of several phosphorous-related compounds. Our findings highlight the intricate interplay between growth, hormonal regulation, metabolic reprogramming, and gene expression in response to phosphorus deficiency in sweet potato. This research underscores the importance of understanding nutrient stress responses to enhance sweet potato resilience and inform sustainable agricultural practices. Future research should focus on exploring the potential for genetic and agronomic interventions to mitigate the effects of phosphorus deficiency and optimize sweet potato productivity in challenging environments. Full article

Rare earth elements (REEs) have garnered significant global attention due to their essential role in advanced technologies. Sri Lanka is endowed with various REE-bearing minerals, including the apatite-rich deposit in the Eppawala area, commonly known as Eppawala rock phosphate (ERP). However, direct extraction of REEs from ERP is technically challenging and economically unfeasible. This study introduces a novel, integrated approach for recovering REEs from ERP as a by-product of nitrophosphate fertilizer production. The process involves nitric acid-based acidolysis of apatite, optimized at 10 M nitric acid for 2 h at 70 °C with a pulp density of 2.4 mL/g. During cooling crystallization, 42 wt% of calcium was removed as Ca(NO₃)₂.4H₂O while REEs remained in the solution. REEs were then selectively precipitated as REE phosphates via pH-controlled addition of ammonium hydroxide, minimizing the co-precipitation with calcium. Further separation was achieved through selective dissolution in a sulfuric–phosphoric acid mixture, followed by precipitation as sodium rare earth double sulfates. The process achieved over 90% total REE recovery with extraction efficiencies in the order of Pr > Nd > Ce > Gd > Sm > Y > Dy. Samples were characterized for their phase composition, elemental content, and morphology. The fertilizer results confirmed the successful production of a nutrient-rich nitrophosphate (NP) with 18.2% nitrogen and 13.9% phosphorus (as P₂O₅) with a low moisture content (0.6%) and minimal free acid (0.1%), indicating strong agronomic value and storage stability. This study represents one of the pioneering efforts to valorize Sri Lanka’s apatite through a novel, dual-purpose, and circular approach, recovering REEs while simultaneously producing high-quality fertilizer. Full article

Objectives: In the animal model, we aim to evaluate the bone behavior in two innovative and different laser-treated (L1–L2) titanium implants compared to sandblasted and acid-etched (SBAE) used as control. Materials and Methods: A total of twenty-seven dental implants (8.5 × 3.3 mm) used for the study (Sweden & Martina, Due Carraie Padova-Italy) were placed in three Pelibuey female sheep. Implant surface profilometric, contact angle and EDX analysis were detected. After 15, 30 and 90 days, histological, histomorphometric, SEM-EDX analysis and Bone-to-implant Contact (BIC), Dynamic Osseointegration Index (DOI) and Bone Quality Index (BQI) (as Calcium and Phosphorous atomic percentages ratio) were performed. Results: All surfaces showed relevant profilometric and wettability differences. After 15 days, BIC₁₅ showed great differences in L2 (42.1 ± 2.6) compared to L1 (5.2 ± 3.1) and SBAE (23.3 ± 3.9) as well as after 30 days (L2 (82.4 ± 2.2), L1 (56.2 ± 1.3) and SBAE (77.3 ± 0.4)). After 90 days, relevant lower BIC₉₀ values were detected in L1 (68.4 ± 0.2) compared to L2 (86.4 ± 0.1) and SBAE (86.2 ± 0.6). The DOI showed higher rates of bone growth in L2 after 15 (DOI₁₅ = 2.81) and 30 days (DOI₃₀ = 2.83), compared to L1 (DOI₁₅ = 0.38, DOI₃₀ = 3.40) and SBAE (DOI₁₅ = 1.55, DOI₃₀ = 2.58). The DOI₉₀ drastic slowdown in SBAE (0.96), L1 (0.76), and L2 (0.95) confirmed the Early Osseointegration (EO) as a crucial phase. Moreover, before loading, the lower global BQI in L1 (Ca 44.43 ± 0.08–P 46.14 ± 5.15) and SBAE (Ca 45.31 ± 2.08–P 48.28 ± 1.12) compared to L2 (Ca 79.81 ± 2.08–P 81.85 ± 3.14) allows to assert that osseointegration process and bone healing could not be considered complete if compared to the native bone. Conclusions: The BIC, DOI, and BQI results showed that osseointegration is a dynamic process, confirming the crucial role of surface characteristics able to influence it, especially the early osseointegration (EO) phase. The short-time L2 implants’ higher bone quantity and quality results, compared to L1 and SBAE, suggested the fundamental role of this innovative laser-obtained surface in “secondary stability” and predictable long-term clinical outcomes. Full article

To address severe ammonia gas and dust pollution coupled with resource waste in exhaust gases from urea prilling towers, a production process for gasified biochar-based slow-release fertilizer is proposed to achieve resource recovery of exhaust pollutants. Through phosphoric acid impregnation modification applied to gasified biochar, its ammonia gas adsorption capacity was significantly enhanced, with saturated adsorption capacity increasing from 0.61 mg/g (unmodified) to 32 mg/g. Coupled with the tower-top bag filter, the modified biochar combines with ammonia gas and urea dust in exhaust gases, subsequently forming biochar-based slow-release fertilizer through dehydration and granulation processes. Material balance analysis demonstrates that a single 400,000-ton/year urea prilling tower achieves a daily fertilizer production capacity of 55 tons, with 18% active ingredient content. The nitrogen content can be upgraded to national standards through urea supplementation. Economic analysis demonstrates a total capital investment of USD1.2 million, with an annual net profit of USD0.88 million and a static payback period of 1.36 years. This process not only achieves ammonia gas emission reduction but also converts waste biochar into high-value fertilizer. It displays dual advantages of environmental benefits and economic feasibility and provides an innovative solution for resource utilization of the exhaust gases from the urea prilling process. Full article

The overuse of synthetic nitrogen fertilizer in vineyards degrades soil quality and poses environmental risks. Partial substitution of synthetic nitrogen with organic alternatives may enhance grapevine performance and soil sustainability, depending on the substitution rate. This study evaluated the effects of replacing synthetic nitrogen with composted spent mushroom substrate at five different rates (0%, 25%, 50%, 75%, and 100%, denoted as NOS, OS-25, OS-50, OS-75, and OS-100, respectively) and a control with no nitrogen fertilization applied (CK), on soil fertility, root growth, and photosynthetic performance in grapevine seedlings. Compared to CK, nitrogen fertilization and organic substitution significantly increased soil electrical conductivity, organic matter, and macronutrient contents, but had no significant effect on soil pH. Organic substitution markedly improved leaf photosynthetic capacity in the summer, with the highest rates observed under OS-25, exceeding CK and NOS by 32.98–63.19% and 13.93–27.38%, respectively. Root growth was also significantly enhanced by organic substitution, with OS-25 exhibiting the best performance. Fine roots in the 0.0–0.5 mm diameter class were dominant, accounting for 56.88–63.06% of total root length and 96.22–97.31% of total root tip count. Increasing substitution rates beyond 25% yielded no further improvements in photosynthesis or root growth. Mantel test analysis indicated strong positive correlations between soil fertility parameters (e.g., alkali-hydrolyzable nitrogen, available phosphorous and potassium) and both photosynthetic efficiency and root growth. These findings suggest that an appropriate substitution rate (i.e., 25%) of organic nitrogen using spent mushroom substrate effectively improves soil fertility, simultaneously optimizing photosynthetic capacity and root growth of grapevine seedlings. Full article

Photoconversion covers (PCCs) are specialized materials designed to modify light conditions in greenhouses, thereby enhancing plant growth and development. Recently, extensive research and development efforts have focused on improving and characterizing both components of PCCs: the cover material and the photoconversion agent (phosphor(s)). Given that the true impact of PCCs on plant growth can only be assessed through greenhouse experiments, while surveying recent publications from 2020 to 2024, in this review, we specifically tried to focus on such experiments. A total of 58 studies on PCCs for greenhouse applications were analyzed. Of those, 26 studies introduced novel materials, including phosphors and PCCs, with the potential to enhance plant growth, although greenhouse experiments were not conducted to evaluate their performance. The remaining 32 studies provided experimental data on PCC efficiency in promoting plant growth through plant-based experiments. To summarize and compare the findings from these greenhouse experiments, in this work, we systematically classify plant growth parameters and examine their application across the surveyed studies. Full article

Soil microorganisms are crucial in global biogeochemical cycles, impacting ecosystems’ energy flows and material cycling. This study, via high-throughput sequencing in four forests—the original Larix gmelinii (Rupr.) Kuzen. forest (LG), the conifer–broad-leaved mixed Pinus sylvestris var. mongolica Litv. forest (PS), the original pure Betula platyphylla Sukaczev forest (BP), and the original pure Populus L. forest (PL) in Shuanghe National Nature Reserve, Daxing’anling mountains—explored soil microbial community structures and diversities. The results indicated that the BP and PL forests had the lowest soil bacterial ACE and Chao1 indices, and the original pure birch forest’s Shannon index was higher than that of the poplar forest. The soil’s fungal Chao1 index of the birch forest was higher than that of the larch forests. Bradyrhizobium and Roseiarcus were the dominant soil bacterial genera; the dominant soil fungal genera were Podila, Russula, and Sebacina. RDA and mantel analyses indicated that soil microbial community structures varied across forest types mainly because of the effective phosphorous and pH levels, soil’s total nitrogen level, and available phosphorus level. This study offers a scientific foundation for cold-temperate-forest ecosystem management regarding soil microbial diversity and community structural changes in different forest types. Full article

The mesocarp, a by-product of coconut production, consists of a fibrous outer layer and a medullary tissue. These fibers can be utilized as an alternative source for producing activated carbon (AC). This study presents a method for producing activated carbon from coconut mesocarp fibers (CMFs) using a phosphoric acid (H₃PO₄) solution as the activating agent. The chemical activation process involves two stages: (1) carbonization of the CMFs, and (2) activation with H₃PO₄ at elevated temperatures. AC was characterized by its structural, thermal, surface morphological, and elemental properties. The resulting AC developed a lamellar structure with a porous network. Notably, the AC treated with a 60% v/v H₃PO₄ solution demonstrated a BET adsorption surface area of 1508 m²/g, a total pore volume of 0.871 cm³/g, and an average pore diameter of 2.20 nm. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of aromatic rings in the AC, while thermogravimetric analysis showed that the AC decomposed at 428 °C, compared to 418 °C for the non-activated carbon. Elemental analysis revealed a 9.04% increase in carbon content in the AC. Producing activated carbon from coconut mesocarp fibers offers a cost-effective method to generate high-surface-area activated carbon from agro-industrial waste. Full article

From 1998 to 2024, we collected field samples at 45 selected lakes in Yellowstone National Park during the months of April through October. We estimated inflows, outflows, and Secchi depths for most lakes. We analyzed the samples for total phosphorous and chlorophyll-a. We used these data to classify the lake trophic states using the Carlson TSI (CTSI), Vollenweider (VW), and Larsen–Mercier (LM) models to assess how trophic states evolved over this 26-year period. This longitudinal dataset is unique because of its extensive 26-year time span gathered from difficult-to-access locations. We found that the data depended on lake size, lake elevation, and the month when data were collected. Most of the lakes exhibit mesotrophic conditions, with variations depending on the trophic state model used. The CTSI distribution shows median values typically between 40 and 55, while the VW and LM index distributions present a somewhat similar pattern but with fewer lakes categorized due to data requirements. We visualized temporal patterns using heatmaps and analyzed trends using the Mann–Kendall test to identify trends and if they were statistically significant. We found only four lakes with statistically significantly increasing trends and two with decreasing trends. Because of the difference in the months when data were collected, the increasing trends in three of the lakes are less certain. We found that, except for four lakes, the trophic states of Yellowstone lakes were maintained or improved over this ~20-year period. Only the trophic state of Nymph Lake clearly deteriorated. The remaining lakes had stable trophic states, with three having weak evidence of worsening conditions. This long-term dataset, which we publish for others’ use, provides an opportunity to better understand eutrophication processes and water quality dynamics in Yellowstone, providing critical information for park management and conservation efforts. Full article

The results of our recent research revealed that biologically synthesized silver nanoparticles (bio-AgNPs) applied to several-day-old pea (Pisum sativum L.) plants or used for seed nanopriming protected pea plants against selected fungal pathogens. However, the susceptibility of pea to bio-AgNPs during seed germination remains mostly unknown. Therefore, in this study, we investigated the cells’ viability, ROS generation, total antioxidant capacity, the activity of selected antioxidant enzymes, and changes in the polar metabolite profiles of 4-day-old pea seedlings developed in water (control) and water suspensions of bio-AgNPs (at 50 and 200 mg/L). The bio-AgNPs did not negatively affect pea seeds’ germination, early seedlings’ growth, and root tips cells’ viability (at both tested concentrations). In the root, the bio-AgNPs at a lower concentration (50 mg/L) stimulated ROS generation. Nanoparticles enhanced peroxidase activity in root and the total antioxidant capacity in epicotyl. Increased levels of malate, phosphoric acid, proline, GABA, and alanine were observed in root and epicotyl of pea seedlings developed at 50 mg/L of bio-AgNPs. A higher concentration affected the tricarboxylic acid cycle and nitrogen metabolism. Bio-AgNPs alerted oxidative homeostasis and primary metabolism of pea seedlings but did not exceed a certain threshold limit and thus did not injure pea at an early stage of seedling development. Full article

In recent decades, land abandonment due to socioeconomic issues has been a widespread process in different areas of the Mediterranean, altering landscapes and affecting soil properties and erosion processes. The aim of this research was to assess the impact of land use and land cover change on soil properties and sediment composition produced after seasonal rainfall. Mediterranean open forest (OF), pine afforestation (PA), thinned pine (TPA) and barren land (BL) land use/land covers were compared. We analyzed the soil characteristics and sediments that were collected under each form of land use and management across seven seasonal campaigns between July 2016 and September 2017. The relationships between soil particle size, soil organic carbon (SOC) and its fractions, key nutrients (nitrogen, phosphorous, potassium and sulfur) and rainfall characteristics were evaluated. Sediment loads from runoff, collected in trap MATs in monitoring areas under OF and PA, were similar in both quantity and composition. However, the amount of sediment increased after thinning, though it remained significantly lower than in BL. Sediment loads were driven by total rainfall in OF and in TPA, while rainfall erosivity had a clear impact in PA and BL. Afforestation helped to maintain SOC and nutrient levels comparable to those in OF, which were significantly higher than in BL. Nitrogen and phosphorous losses were mainly governed by the total amount of precipitation. However, the effect of rainfall on potassium and sulfur losses was not clearly evident. Full article

This study focused on the physicochemical characteristics of the fermented products (FP) produced by Bacillus amyloliquefaciens CU33 (CU33) from soybean meal with 70% moisture. Additionally, it investigated the effects of adding FP to starter on the growth performance, general health performance, blood clinical biochemistry, and immunity of Alpine goat kids during the weaning period. Forty 14-day-old male Alpine goat kids were randomly assigned into starter supplementations of 0, 0.1, 0.3, or 0.5% CU33 FP for 8 weeks, and each goat kid was individually raised in stainless steel cage (width 70 cm × height 70 cm × depth 80 cm). The moisture after fermentation was linearly decreased as fermentation time increased (p < 0.05), and the pH value and Bacillus-like counts reached the highest at 24 h of fermentation. The activity of neutral protease and alkaline protease, the content of surfactin and γ-PGA, the viscosity, and the odor of CU33 FP were linearly increased as fermentation time increased (p < 0.05). The neutral protease activity, surfactin, γ-PGA, and viscosity increased after drying, whereas the moisture, pH value, Bacillus-like counts, and odor decreased (p < 0.05). During the pre-weaning period (0–4 weeks), the body weight gain (BWG) of the 0.1% CU33 FP group was higher than that of the control group (p < 0.05), and all CU33 FP groups showed a better feed conversion ratio (FCR) than the control group (p < 0.05). During the post-weaning period (4–8 weeks) and throughout the entire experimental period (0–8 weeks), the BWG and FCR of all CU33 FP groups were better than those of the control group (p < 0.05). Furthermore, both BWG and FCR improved linearly as the dietary level of CU33 FP increased (p < 0.05). Simultaneously, the fecal consistency index at 0–4 and 4–8 weeks and the coliform counts in the rectum at 4 weeks linearly decreased (p < 0.05), and the Bacillus-like counts in the rectum linearly increased at 4 and 8 weeks (p < 0.05). Phosphorous (P), total protein (TP), blood urea nitrogen (BUN) in serum at 8 weeks, and the oxidative burst capacity at 4 weeks linearly increased as the dietary level of CU33 FP increased, but the skin sensitization test showed a quadratic curve, and the 0.1% CU33 FP group had the lowest performance (p < 0.05). In conclusion, dietary supplementation with 0.1% of CU33 FP can improve the growth performance, diarrhea status, and oxidative burst capacity of Alpine goat kids, showing the potential to be a feed additive. Full article

Adsorption is a popular method for the recovery of low-grade lithium. It is a low-cost and highly efficient way to treat solutions with low lithium concentrations. The impurity content determines the industrial application. This study investigated a novel strategy to remove divalent cations from a desorption solution containing Mg²⁺, Ca²⁺, and Mn²⁺, generated by a manganese absorbent using an organophosphoric acid, followed by precipitation of lithium carbonate from the concentrated raffinate by evaporation. Di(2-ethylhexyl)phosphoric acid (P204) was selected as the preferred extractant. The saponification method and degree of saponification were determined, and the extraction parameters (pH, extractant concentration, and phase ratio) were investigated. A three-stage countercurrent extraction process was tested. Removal efficiencies of Mg²⁺, Ca²⁺, and Mn²⁺ from the manganese-containing desorption solution exceeded 99%, leaving <1.0 mg/L divalent cations in the raffinate. The raffinate was evaporated and concentrated to >23 g/L lithium. The total concentration of divalent cations in the lithium-rich solution was approximately 10.0 mg/L. Further conversion with sodium carbonate was carried out to prepare a battery-grade lithium carbonate product with a purity of 99.83%. The present work may provide a novel means of lithium recovery from a manganese-containing desorption solution. Full article

Water stress and nutrient stress are major limiting factors affecting crop productivity. Biochar-based organic fertilizers improve soil nutrient availability, water use efficiency (WUE), and crop yields under these adverse conditions. This study investigated the mechanistic effects of biochar–bokashi mixtures under a controlled glasshouse pot experiment on soil fertility, available nutrients, soil moisture, plant water use efficiency (PWUE), and wheat yield parameters under three moisture levels. Four treatments were included, (1) a control, (2) bokashi only, (3) 1% biochar + bokashi, and (4) 2% biochar + bokashi, under 30% (IR₃₀), 50% (IR₅₀), and 60% (IR₆₀) field capacity, totaling twelve treatments in a completely randomized design with three replications. The combined bokashi–biochar application significantly (p < 0.05) improved growth parameters and yields, including plant height, number of fertile tillers (NFT), number of spikes (NS), spike length (SL), 1000-grain weight, biological yield (BY), root biomass, and grain yield (GY), compared to the control and bokashi-only treatments. Bokashi with 1% biochar exhibited superior agronomic performance over the other treatments, including 2% biochar. Biochar addition enhanced soil moisture and PWUE across irrigation levels. Bokashi–biochar treatments under IR₃₀ outperformed the control and bokashi-only treatments under IR₆₀, highlighting biochar’s effectiveness in alleviating water stress and increasing yields. Moreover, co-application significantly increased soil pH while enhancing the organic carbon, total nitrogen, available phosphorous and exchangeable potassium nutrient levels, which positively correlated with yield. Bokashi–biochar mixtures have been proven to be an effective strategy to enhance soil fertility, increase soil moisture to alleviate water stress and support sustainable wheat production under water- and nutrient-limited conditions. Full article