Search Results (145)

The textile industry widely uses reactive anthraquinone dyes, which exhibit strong resistance to color removal and generate substantial volumes of wastewater containing significant quantities of residual dye requiring treatment prior to discharge. As part of a study aimed at reusing rather than discharging spent reactive anthraquinone dyebaths, Reactive Blue 4 (RB4) dye was used in dyeing cotton, and the generated spent dyebaths were biologically decolorized using a fluidized bed reactor (FBR) operated under hypersaline conditions at a salt concentration of 100 g NaCl/L, which is typically found in commercial spent reactive dyebaths. Across five consecutive runs, the FBR achieved a mean decolorization efficiency of 91.2 ± 2.8% within a 6 h incubation period. The quality of cotton dyed with the treated and reused spent dyebaths was evaluated through shade reproducibility and color consistency assessments. Five repetitive dyeings using the biologically decolorized dyebaths showed that the ΔE_cmc fabric color difference values were 0.58~0.80, which were lower than the industry-accepted value of 1.0. This study demonstrates that biologically decolorized spent dyebaths can be effectively reused, offering substantial reductions in water and salt consumption and improving the economic and environmental sustainability of the reactive dyeing process. Full article

In this study, radiation damage in BaFBr and BaF₂ crystals irradiated with 147 MeV ⁸⁴Kr ions up to fluences of (10¹⁰–10¹⁴) ions/cm² was investigated using X-ray excited optical luminescence (XEOL) and pulsed cathodoluminescence (PCL). The effect of oxygen impurities present in the studied crystals was also considered. XEOL spectra revealed bands associated with oxygen impurities occupying halide sites, as well as luminescence bands with maxima at approximately 2.81 eV, 3.7–4 eV, and 2.3 eV. The luminescence at 2.81 eV can be attributed to the recombination of electrons released during X-ray irradiation with holes trapped at specific sites (Type I, PL). The observed highly energetic luminescence is most likely due to perturbed exciton. Such a perturbed exciton can be formed in the configuration F + V_k (${\mathrm{Br}}_2^{-}$) in the presence of the neighboring impurity ion $O^{2-}$. Oxygen impurities play an important role in the formation mechanisms of these centers. High radiation doses lead to crystal degradation. Excitation by a high-power electron pulse induces excitonic luminescence near the oxygen impurity at 4.2 eV. A distinctive feature of the 4.2 eV emission band is its strong intensity at high temperatures. In the decay kinetics of the PCL spectra, a fast component in the nanosecond range dominates, which remains independent of fluence in BaFBr and BaF₂ crystals irradiated with krypton ions. Full article

Cryosat-2 SARin altimetric FBR data facilitates an opportunity to investigate phase differences between inland water radar reflections at the two antennae. With the antennae positioned cross-track, SARin was designed for the recovery of slope over ice margins, but here, it was used to recover off-pointing over inland waters. The ability to measure non-nadir off-pointing is verified using ocean data near the Amazon estuary to determine the satellite roll angle. Over inland waters, off-pointing requires correction to the nadir range and the geographic location of the reflectance. By using an SRTM-based water mask, the number of inland water reflectance increases significantly when off-pointing is considered. Comparisons between altimetric and river heights utilise gauge data at Tabatinga on the Solimões–Amazon. A least-squares adjustment yielded a river slope of −0.03506 ± 0.00003 m/km and a mean velocity of 1.803 ± 0.014 m/s over a river stretch of nearly 290 km. RMSE differences between the gauge and altimetry improve from 0.423 m to 0.404 m when off-pointing is taken into account for nadir inland water returns, showing the asymmetric effect of off-pointing. If all potential off-pointings are considered, the number of measurements increases by 66%, but the RMSE of 0.524 m is higher due to additional errors in the off-pointing corrections. Full article

Intracortical microelectrode arrays (MEAs) are tools for recording and stimulating neural activity, with potential applications in prosthetic control and treatment of neurological disorders. However, when chronically implanted, the long-term functionality of MEAs is hindered by the foreign body response (FBR), characterized by gliosis, neuronal loss, and the formation of a glial scar encapsulating layer. This response begins immediately after implantation and is exacerbated by factors such as brain micromotion and the mechanical mismatch between stiff electrodes and soft brain tissue, leading to signal degradation. Despite progress in mitigating these issues, the underlying mechanisms of the brain’s response to MEA implantation remain unclear, particularly regarding how cells sense and respond to the associated mechanical forces. Mechanosensitive ion channels, such as the Piezo family, are key mediators of cellular responses to mechanical stimuli. In this study, silicon-based NeuroNexus MEAs consisting of four shanks were implanted in the rat somatosensory cortex for sixteen weeks. Weekly neural recordings were conducted to assess signal quality over time, revealing a decline in active electrode yield and signal amplitude. Immunohistochemical analysis showed an increase in GFAP intensity and decreased neuronal density near the implant site. Furthermore, Piezo1—but not Piezo2—was strongly expressed in GFAP-positive astrocytes within 25 µm of the implant. Piezo2 expression appeared relatively uniform within each brain slice, both in and around the MEA implantation site across cortical layers. Our study builds on previous work by demonstrating a potential role of Piezo1 in the chronic FBR induced by MEA implantation over a 16-week period. Our findings highlight Piezo1 as the primary mechanosensitive channel driving chronic FBR, suggesting it may be a target for improving MEA design and long-term functionality. Full article

Extracellular matrix (ECM) bioscaffolds have demonstrated therapeutic potential across a variety of clinical and preclinical applications for tissue repair and regeneration. In parallel, these scaffolds and their components have shown the capacity to modulate the immune response. Unlike synthetic implants, which are often associated with chronic inflammation or fibrotic encapsulation, ECM bioscaffolds interact dynamically with host cells, promoting constructive tissue remodeling. This effect is largely attributed to the preservation of structural and biochemical cues—such as degradation products and matrix-bound nanovesicles (MBV). These cues influence immune cell behavior and support the transition from inflammation to resolution and functional tissue regeneration. However, the immunomodulatory properties of ECM bioscaffolds are dependent on the source tissue and, critically, on the methods used for decellularization. Inadequate removal of cellular components or the presence of residual chemicals can shift the host response towards a pro-inflammatory, non-constructive phenotype, ultimately compromising therapeutic outcomes. This review synthesizes current basic concepts on the innate immune response to ECM bioscaffolds, with particular attention to the inflammatory, proliferative, and remodeling phases following implantation. We explore how specific ECM features shape these responses and distinguish between pro-remodeling and pro-inflammatory outcomes. Additionally, we examine the impact of manufacturing practices and quality control on the preservation of ECM bioactivity. These insights challenge the conventional classification of ECM bioscaffolds as medical devices and support their recognition as biologically active materials with distinct immunoregulatory potential. A deeper understanding of these properties is critical for optimizing clinical applications and guiding the development of updated regulatory frameworks in regenerative medicine. Full article

Immune cells play a pivotal role in orchestrating tissue repair, executing functions such as debris clearance, extracellular matrix remodeling, and modulation of cytokine secretion profiles. However, when their activity is dysregulated or inadequately directed, these same processes can give rise to chronic inflammation and foreign body reactions (FBR), ultimately leading to fibrosis and compromised biomaterial performance. The immunological landscape following injury or biomaterial implantation is profoundly influenced by the physicochemical properties of material surfaces. By strategically tailoring these surface characteristics, it becomes possible to modulate immune cell responses—governing their adhesion, recruitment, proliferation, polarization, and cytokine expression patterns. This review elucidates the multifaceted roles of immune cells in tissue repair and their dynamic interactions with implanted biomaterials. It then explores how specific surface attributes—such as topography, chemistry, stiffness, and wettability—influence immune behavior. Particular emphasis is placed on recent advances in surface modification techniques aimed at engineering next-generation biomaterials that mitigate adverse immune responses while actively promoting regenerative healing. The review concludes by offering critical insights into the future of immunomodulatory biomaterial design, highlighting both emerging opportunities and persisting challenges in the field. Full article

The main aim of this study deals with the potential evaluation of a fluidized bed membrane reactor (FBMR) for hydrogen production as a clean fuel carrier via methanol steam reforming reaction, comparing its performance with other reactors including packed bed membrane reactors (PBMR), fluidized bed reactors (FBR), and packed bed reactors (PBR). For this purpose, a two-dimensional, axisymmetric numerical model was developed using computational fluid dynamics (CFD) to simulate the reactor performances. Model accuracy was validated by comparing the simulation results for PBMR and PB with experimental data, showing an accurate agreement within them. The model was then employed to examine the effects of key operating parameters, including reaction temperature, pressure, steam-to-methanol molar ratio, and gas volumetric space velocity, on reactor performance in terms of methanol conversion, hydrogen yield, hydrogen recovery, and selectivity. At 573 K, 1 bar, a feed molar ratio of 3/1, and a space velocity of 9000 h⁻¹, the PBMR reached the best results in terms of methanol conversion, hydrogen yield, hydrogen recovery, and hydrogen selectivity, such as 67.6%, 69.5%, 14.9%, and 97.1%, respectively. On the other hand, the FBMR demonstrated superior performance with respect to the latter reaching a methanol conversion of 98.3%, hydrogen yield of 95.8%, hydrogen recovery of 74.5%, and hydrogen selectivity of 97.4%. These findings indicate that the FBMR offers significantly better performance than the other reactor types studied in this work, making it a highly efficient method for hydrogen production through methanol steam reforming, and a promising pathway for clean energy generation. Full article

This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which limit its direct reuse due to phytotoxicity. A native strain of Aspergillus sp., isolated from OP, was employed as the biological agent, while grape pomace (GP) was added as a co-substrate to enhance substrate structure. Fermentations were conducted at two scales, Petri dishes (20 g) and a fixed-bed bioreactor (FBR, 2 kg), under controlled conditions (25 °C, 7 days). Key parameters monitored included dry and wet weight loss, pH, color, phenolic content, and enzymatic activity. Significant reductions in color and polyphenol content were achieved, reaching 68% in Petri dishes and 88.1% in the FBR, respectively. In the FBR, simultaneous monitoring of dry and wet weight loss enabled the estimation of fungal biotransformation, revealing a hysteresis phenomenon not previously reported in SSF studies. Enzymes such as xylanase, endopolygalacturonase, cellulase, and tannase exhibited peak activities between 150 and 180 h, with maximum values of 424.6 U·g⁻¹, 153.6 U·g⁻¹, 67.43 U·g⁻¹, and 6.72 U·g⁻¹, respectively. The experimental data for weight loss, enzyme production, and phenolic reduction were accurately described by logistic and first-order models. These findings demonstrate the high metabolic efficiency of the fungal isolate under SSF conditions and support the feasibility of scaling up this process. The proposed strategy offers a low-cost and sustainable solution for OP valorization, aligning with circular economy principles by transforming agro-industrial residues into valuable bioproducts. Full article

Recently, the utilization of nanomaterials has been gaining popularity in soil improvement procedures. The aim of this study is to investigate the feasibility of using nano-MgO (NM) along with fibers (FBRs) to improve clay soil’s load-bearing capacity and settlement by using both conventional and model experiments. First, the optimum water content values for NM–clay mixtures were determined by compaction tests. For mixtures prepared with the optimum water content, the addition of 1.5% NM alone resulted in a 1.33-times improvement in bearing capacity, and the addition of 1.5% 90 mm FBRs alone led to a 1.83-times improvement. Utilizing 1.0% NM and 1.5% FBRs at 90 mm long resulted in a 3.07-times improvement in bearing capacity. The temperature of the mixing water was found not to be a significant parameter, and curing duration impacted the results only for NM addition. Significant settlement improvements were achieved by adding the two materials together. Therefore, utilizing NM and FBRs together resulted in an optimal outcome for clay soil. Full article

Background: Effective pain management in children is essential, particularly when administering local anaesthesia. This study was undertaken to compare pain perception in children after application of pre-cooled and plain topical anaesthetic gel during local anaesthetic administration. Methods: A randomised, single-blinded controlled trial was conducted among 51 children between the ages of 6 and 12, visiting the paediatric clinic, Jazan (REC-45/10/1070). Children were allocated into one of the following three groups using a simple randomisation having a 1:1:1 allocation ratio into Group I (n = 17): Plain topical anaesthetic gel, Group II (n = 17): Pre-Cooled topical anaesthetic gel, and Group III (n = 17). An ice pack was applied for a period of 1 min at the injection site. The intensity of pain and the behaviour of the children were assessed using Face, Leg, Activity, Cry, Consolability (FLACC), the Modified Wong–Baker Scale (WBS) and the Frankel Behaviour Rating Scale (FBRS). Results: A significant difference in FBRS scores was observed during anaesthesia, with the highest median score [3 (3,3)] in the pre-cooled topical anaesthetic gel group (p value < 0.001). FLACC scores varied significantly among groups, with the ice pack group [3 (3, 3)] and [4 (4, 5)] showing the highest median score (p value < 0.001). WBS scores also differed significantly between groups (p value < 0.001) with a lower value in the pre-cooled topical gel group [0 (0, 0), 2 (0, 2)]. Conclusions: This study concluded that, the use of a pre-cooled topical anaesthetic gel before LA administration reduced the pain better than that of plain anaesthetic gel and ice pack application at the injection site during infiltration. Full article

This paper presents a comprehensive summary of recent advances in circuit topologies for piezoelectric energy harvesting, leading to self-powered systems (SPSs), covering the full-bridge rectifier (FBR) and half-bridge rectifier (HBR), AC-DC converters, and maximum power point tracking (MPPT) techniques. These approaches are analyzed with respect to their advantages, limitations, and overall impact on energy harvesting efficiency. Th work explores alternative methods that leverage phase shifting between voltage and current waveform components to enhance conversion performance. Additionally, it provides detailed insights into advanced design strategies, including adaptive power management algorithms, low-power control techniques, and complex impedance matching. The paper also addresses the fundamental principles and challenges of converting mechanical vibrations into electrical energy. Experimental results and performance metrics are reviewed, particularly in relation to hybrid approaches, load impedance, vibration frequency, and power conditioning requirements in energy harvesting systems. This review aims to provide researchers and engineers with a critical understanding of the current state of the art, key challenges, and emerging opportunities in piezoelectric energy harvesting. By examining recent developments, it offers valuable insights into optimizing interface circuit design for the development of efficient and self-sustaining piezoelectric energy harvesting systems. Full article

A negative value of the void reactivity coefficient (α_V) is one of the most important passive safety properties for the operation of nuclear reactor. Herein, are presented calculated values of the void reactivity coefficient for different geometries of reactors cooled by liquid lead (LFR) and sodium (SFR) with U-238-Pu-239 and Th-232-U-233 fuels. The calculations were carried out for the reactors filled with either one or two types of fuel assemblies. The most interesting results are obtained for reactor filled with two different types of fuel assemblies (hybrid reactor). Hybrid reactors consist of central and peripheral types of fuel assemblies using low enrichment fuel and high enrichment fuel, respectively. Both hybrid reactors based on the uranium cycle (U-cycle) and the thorium cycle (Th-cycle) can maintain a negative void reactivity coefficient value for wide range of reactor parameters. The calculation results of the hybrid reactor matched those from FBR-IME reactor. Full article

This study presents the development of a kinetic model for the gasification of biochar with carbon dioxide and compares the results obtained using a thermogravimetric analyzer (TGA) and a fluidized bed reactor (FBR). The kinetic experiments investigated the effects of the CO₂ partial pressure (0.33–1 atm), temperature (800–1000 °C), and CO₂/C ratio (3.5–10.5). Three structural models, the shrinking core model (SCM), volumetric model (VM), and power-law model (PLM), were evaluated for their ability to predict experimental results. The results demonstrated that increasing the temperature, CO₂ partial pressure, and CO₂/C ratio enhanced the gasification rate, reducing the time required for complete biochar conversion. The apparent activation energy for both reactors was similar (156–159 MJ/kmol), with reaction orders of 0.4–0.49. However, the kinetic models varied significantly between setups. In the TGA, the PLM provided the best fit to experimental data, with standard deviations of 2.6–9%, while in the FBR, the SCM was most accurate, yielding an average deviation of 1.5%. The SCM effectively described the layer-by-layer char consumption, where gasification slowed at high conversion levels. Conversely, the PLM for the TGA revealed a unique mathematical function not aligned with traditional models, indicating localized reaction behaviors. This study highlights the inability to directly extrapolate TGA-derived kinetic models to FBR systems, underscoring the distinct mechanisms governing char consumption in each reactor type. These findings provide critical insights for optimizing biochar gasification across diverse reactor configurations. Full article

Spent mushroom substrate (SMS), spent coffee grounds from espresso production (SCG), faba bean harvest residues (FBR), pistachio shells (PS) wheat straw (WS) (control) agro-industrial waste were combined in different ratios, with or without supplements (wheat bran, soybean flour), to create novel substrates for Pleurotus columbinus growth. The impact of the substrates on the mycelial growth rate (Kr), biomass production, laccase, total cellulases and carbohydrate synthesis, along with the C and N consumption by P. columbinus, were examined in fully colonized substrates. The incubation period, earliness and biological efficiency (B.E.) (%) were also determined. Then, the intracellular polysaccharide (ICP) contents of the P. columbinus produced mushrooms were evaluated in the most promising substrates. P. columbinus was grown successfully in a wide range of C/N ratios of substrates and the fastest Kr (7.6 mm/d) was detected on the 70 SMS-30 FBR, without supplements, whereas substrates consisting of SCG enhanced biomass production (700.0–803.7 mg/g d.w.). SMS and PS or SCG led to the shortest incubation and earliness period of P. columbinus. The C content was reduced and the N content was substantially increased in all the colonized substrates. The 70 SMS-30 FBR and 80 SMS considerably enhanced the laccase production (up to 59,933.4 U/g d.w.) and substrates consisting of PS promoted total cellulases activities. Greater amounts of carbohydrates (3.8–17.4 mg/g d.w.) than that in the control were recorded for all the substrates. The combination of SMS and SCG or WS led to the highest B.E. values (59.3–87.1%) and ICP amounts (34.7–45.9%, w/w), regardless of the supplement addition. These findings support the effective utilization of agro-industrial waste in P. columbinus cultivation, producing high-value-added compounds and supporting mushroom growth. Full article

This study used in situ modulation excitation spectroscopy (MES) with varying frequencies in a single experiment to identify surface species during ethanol oxidation on Au/SiO₂, Au/TiO₂, Au/ZnO, and Au/SrTiO₃. Fixed-bed reactor (FBR) tests (1 kPa ethanol, 1.5 kPa O₂, 513 K) showed that Au/SiO₂ and Au/SrTiO₃ had higher ethanol conversions. Au/SiO₂ favored acetaldehyde, while Au/SrTiO₃ yielded more acetates (acetic acid and ethyl acetate). Operando modulation excitation (ME)–phase sensitive detection (PSD)–DRIFTS, with ethanol and oxygen modulation, identified surface ethanol, acetaldehyde, acetates, ethoxy, and hydroxyl species. Oxygen modulation showed charge transfer to supports in Au/TiO₂ and Au/ZnO. At the fundamental frequency (f₀ = 1/90 Hz), ME–PSD–DRIFTS showed minimal adsorbed ethanol on Au/SiO₂, indicating high ethanol conversion. Au/SrTiO₃ had higher acetaldehyde consumption, correlating with increased acetates, consistent with FBR results. ME–PSD–DRIFTS at lower frequencies (0.07f₀, 0.5 f₀) and higher harmonics (2f₀, 3f₀) showed rapid ethoxy formation/decomposition, and slower acetaldehyde reactions, confirming acetaldehyde as a primary product and acetates as secondary products. Oxygen modulation revealed rapid hydrogen spillover and hydroxyl changes. Overall, operando spectroscopy via mass spectrometry confirmed the FBR findings. Full article