Decrease In Rate Of Degradation Research Articles

Angiogenesis-osteogenesis coupling and anti-osteoclastogenesis zoledronate intermixed calcium silicate metal-organic/inorganic hybrid coating on biodegradable zinc-based intramedullary nails for osteoporotic fracture healing

Osteoporotic (OP) fractures remain a tough clinical challenge owing to their impaired healing outcome, which requires novel biomaterials with osteogenicity for effective healing. Metallic zinc (Zn) is attracting increasing attention for biodegradable intramedullary nails (IMNs) for OP fracture healing thanks to their comprehensive mechanical properties, biosafety, and bioactivity. However, the multiple biofunctions required for OP fracture healing have not been fully met by Zn. Herein, a zoledronate (ZA)-mediated calcium-zinc silicate (Ca(Zn)Si) metal-organic/inorganic hybrid coating was fabricated on Zn-based IMN by coordination chemistry driven via interactions between ZA and Ca2+/Zn2+ as well as in-situ directional growth of Ca(Zn)Si phase. The ZA&Ca(Zn)Si hybrid coating exhibited a homogeneous micro/nanostructure with a granular morphology, which prevented premature fracture failure of IMN in rat femur by ameliorating corrosion mode and decreasing degradation rate of the Zn matrix. More importantly, this hybrid coating enabled sustained release of Zn2+/Ca2+/Si4+ and ZA in the long term, achieving a remarkable effect on vascularized bone regeneration. The coated IMN enhanced angiogenesis–osteogenesis coupling through autocrine and paracrine effects between endothelial cells and bone marrow mesenchymal stem cells. Osteoclastogenesis was repressed by Zn2+ and ZA. This approach offers a new strategy for surface-engineering of biodegradable metals for bone fracture healing.

Enhanced degradation of crude oil by immobilized bacterial consortium through eliminating microbial flocculation towards crude oil

Microbial degradation is considered an effective and sustainable technique for the remediation of oily sludge; thus, the acquisition of crude oil-degrading bacteria is crucial for effective bioremediation. This study introduces a novel domestication-enrichment-isolation (DEI) strategy to isolate crude oil-degrading bacteria from oily sludge. Two strains, Rhodococcus rhodochrous JS-24 (R.rh) and Gordonia cholesterolivorans JS-13 (G.ch), demonstrated the highest degradation rates of 53.7% and 34.6%, respectively, within 7 days. While no synergistic effect was observed with their combined use in free bacterial consortia, and the overall degradation rate decreased to 51.9 %, which was weaker than that of R. rh treatment alone. The decrease in degradation rate is attributed to microbial flocculation towards crude oil: most droplets of crude oil were encapsulated into spherical aggregations by G. ch, thereby hindering the contact and degradation of droplets by R. rh. In contrast, immobilization technology significantly enhanced crude oil degradation by eliminating this flocculation effect. The immobilized bacterial consortium achieved a 95.5% degradation rate, representing the highest degradation rate reported for bacterial consortia. This study reveals for the first time that the side effects of bioflocculation on crude oil degradation and provides guidance for the construction of bacterial consortium.

Interfacial engineering of (Ce,Zr)O2 composite barrier layers for enhancing the durability of solid oxide fuel cells

The dense GdxCe1-xO2 (GDC) barrier layer can't prevent the diffusion of small amounts of Sr through grain boundaries. Recent studies indicate that the (Ce,Zr)O2 composite, placed between GDC and YSZ (Y2O3 stabilized ZrO2) electrolyte, can effectively suppress SrZrO3 formation. In this study, we successfully designed and prepared an anode-supported solid oxide fuel cell (SOFC) with a dense GDC/IDL (interdiffusion layer) composite barrier layer, demonstrates excellent inhibition of elemental diffusion through grain boundaries. Compared with the cell with a single dense GDC barrier layer, the cell with GDC/IDL composite barrier layer exhibits largely improved durability, with a two-fold decreased degradation rate of 2.7 %/kh, operated under constant current density of 400 mA/cm2 at 720 °C. The cell with GDC/IDL barrier layer presents decreased initial performances, with lager Rohm of 0.085 Ω cm2 than 0.075 Ω cm2, and smaller initial Pmax of 0.905 W/cm2 than 1.019 W/cm2 at 750 °C. However, the cell performance surpasses the cell with single GDC barrier after 230 h. Thus, we obtain a new strategy to achieve improved cell durability by sacrificing the cell's initial performance. The in-situ constructed continuous and dense GDC/IDL composite optimizes the electrolyte/cathode interface while maintaining decent electrochemical performance, providing a new horizon to design and prepare high performance and durable SOFCs.

Fabrication, physicochemical properties, and cytocompatibility of 3D-printed Sr2MgSi2O7 bioceramic scaffolds calcined at different temperature for bone repair

3D-printed bioactive ceramic scaffolds hold significant promise for addressing critical-size bone defects, owing to their biodegradable and osteogenic properties. Numerous 3D-printed silicate-based (e.g., Sr2MgSi2O7) ceramic scaffolds have been developed, but the rapid degradation and insufficient mechanical properties of which impede their application efficacy. Despite recognizing the pivotal role of calcination temperature in shaping the physicochemical and biological attributes of 3D-printed scaffolds, its specific influence on Sr2MgSi2O7 bioceramics remains ambiguous. This study elucidated the fabrication, physicochemical properties, and cytocompatibility of 3D-printed Sr2MgSi2O7 ceramic scaffolds calcined at different temperatures. The findings revealed a significant enhancement in compressive strength (up to 19.9 MPa) and a decrease in degradation rate with increasing calcination temperature. Compared to conventional tricalcium phosphate scaffolds, Sr2MgSi2O7 scaffold demonstrated superior osteogenic potential, particularly when calcined at 1250°C. With commendable mechanical strength and remarkable osteogenic capabilities, the Sr2MgSi2O7 scaffold emerges a promising avenue for repairing critical-size bone defects.

As a service or a product? A comparison of electric vehicle battery supply models

In response to the challenges posed by high costs and rapid degradation of electric vehicle (EV) batteries, Battery as a Service (BaaS) is introduced as a new EV battery supply model, alongside the traditional model of Battery as a Product (BaaP). Under this background, how to choose a battery supply model is a major strategic problem. Through game theory approach, we analyze and compare the BaaS and BaaP models under a durable goods framework. Firstly, we find that the BaaS model is more profitable than the BaaP model when battery cost or degradation rate is excessively high. The firm under BaaS can relieve cost pressures by selectively retaining used batteries and reducing the price threshold for consumers to acquire batteries. Secondly, through premature disposal of used batteries, a firm can endogenously determine the quality of battery service, making the BaaS model more profitable when battery cost or degradation rate is excessively low. Thirdly, we show that the firm under BaaS always benefits from the decrease of battery degradation rate. However, a lower battery degradation rate may reduce the firm’s profit under BaaP because of the cannibalization effect from the secondary market.

Perturbation of periodic spot-generation balance leads to diversified pigmentation patterning of harlequin Phalaenopsis orchids: in silico prediction

BackgroundA retrotransposon HORT1 in the promoter of the anthocyanin activator gene PeMYB11, microRNA858 (miR858) that targets PeMYB11, and a repressor PeMYBx have been implicated in pigmentation patterning diversity of harlequin Phalaenopsis orchids. However, the interrelationship among them remains to be elucidated.ResultsTo understand how these factors interact to generate anthocyanin spots in Phalaenopsis, we successfully developed a mathematical model based on the known reaction–diffusion system to simulate their interplay and refined the conceptual biological model. Intriguingly, the expression of both PeMYBx and PeMYB11 were in phase for purple spot formation, even though they showed adverse effects on anthocyanin accumulations. An increase in the self-activation rate of PeMYB11 resulted in the increased size of purple spots, but no effects on spot fusion. Decreased degradation rate of miR858 in the purple regions, led to disruption of the formation of spotted pigmentation patterning and a full-red pigmentation pattern. Significantly, the reduced miR858 level promotes the fusion of large dark purple dots induced by the solo-LTR of HORT1, eventually generating the purple patches. In addition, the spatially heterogeneous insertion of HORT1 caused by the remnant solo-LTR of HORT1 derived from random homologous unequal recombination of HORT1 in individual cells of floral organs could explain the diverse pigmentation patterning of harlequin Phalaenopsis.ConclusionsThis devised model explains how HORT1 and miR858 regulate the formation of the pigmentation patterning and holds great promise for developing efficient and innovative approaches to breeding harlequin Phalaenopsis orchids.

Gelatin-containing functionally graded calcium sulfate/bioactive glass bone tissue engineering scaffold

One of the challenges and limitations of bone tissue engineering includes fast degradation rates, reduced bioactivity, donor site morbidity, and unresolved risks of pathogen transmission. In the field of bone tissue engineering, gradient materials are promising for treating bone defects because they can create graded structures and compositions similar to natural bone. By controlling the amount of components in the structure, the degradation rate, bioactivity, and osteogenic capacity can be manipulated. In the current study, a gradient, multilayer, porous nanocomposite of calcium sulfate/glass (Gn CS/BG) with a gelatin coating (Gn CS/BG-Gel) was prepared using rotational casting technique. The SEM results showed an average pore size of approximately 400 μm within the Gn CS/BG-Gel nanocomposite. An elastic modulus (E) of around 240 MPa and an ultimate tensile strength (σ) of approximately 5.5 MPa were achieved for Gn CS/BG-Gel nanocomposite. The degradation analysis in a dynamic tris-buffer environment revealed a degradation rate of 68 % over a 63-day period, with a decrease in degradation rate as the bioactive glass (BG) content increased in each layer, indicating the influence of BG on the degradation process. The bioactivity results in a dynamic simulated body fluid suggested that increased BG content in each layer promoted hydroxyapatite formation, indicating improved bioactive behavior. The evaluation of ion release with ICP-OES, MTT and Acridine Orange assays using human bone marrow-derived mesenchymal stem cells (hBMSCs) confirmed the non-toxic nature of Gn CS/BG-Gel. Assessments of alkaline phosphatase (ALP) activity, calcium content, Alizarin Red staining and cell attachment behavior substantiated the osteogenic potential of Gn CS/BG-Gel. Collectively, the three-dimensional structure along with the Gn CS/BG-Gel composition contributed to the enhanced cellular responses. These findings hold significant promise for the development of biomaterials with potential applications in bone tissue engineering, and they contribute valuable insights to the field.

3D-printing of alginate/gelatin scaffold loading tannic acid@ZIF-8 for wound healing: In vitro and in vivo studies

In the present study, ZIF-8 metal-organic framework (MOF) modified with Tannic acid (TA@ZIF-8) was synthesized and impregnated in alginate-gelatin (Alg-Gel) hydrogel. The Alg-Gel scaffolds containing 0, 5, and 10 % of TA@ZIF-8 were fabricated through the 3D printing method specifically denoted as Alg-Gel 0 %, Alg-Gel 5 %, and Alg-Gel 10 %. XRD, FTIR, FESEM, and EDX physically and chemically characterized the synthesized ZIF-8 and TA@ZIF-8 MOFs. Besides, Alg-Gel containing TA@ZIF-8 prepared scaffolds and their biological activity were also evaluated. SEM images verified the nano-size formation of MOFs. Improved swelling and decreased degradation rates after adding TA@ZIF-8 were also reported. Increased compression strength from 0.628 to 1.63 MPa in Alg-Gel 0 % and Alg-Gel 10 %, respectively, and a 2.19 increase in elastic modulus in Alg-Gel 10 % scaffolds were exhibited. Biological activity of scaffolds, including Live-dead and Cell adhesion, antibacterial, in-vivo, and immunohistochemistry assays, demonstrated desirable fibroblast cell proliferation and adhesion, increased bacterial growth inhibition zone, accelerated wound closure and improved expression of anti-inflammatory cytokines in Alg-Gel 10 % scaffolds. The findings of this study confirm that Alg-Gel 10 % scaffolds promote full-thickness wound healing and could be considered a potential candidate for full-thickness wound treatment purposes.

Experimental and Computational Analyses of Sustainable Approaches in Railways

Railway transportation is widely recognized as an environment-friendly and sustainable means for conveying freight and passengers over long distances. This article investigates the effectiveness of utilizing scrap tire rubber granules and geosynthetics to enhance track performance in response to the growing demands for railway transport and the consequent escalation of train-induced loading. A multi-faceted methodology, incorporating experimental, numerical, and analytical techniques, is employed to examine the efficacy of these sustainable approaches. Results from three-dimensional (3D) finite element (FE) analyses conducted on slab tracks for high-speed railways reveal that the addition of a resilient layer, comprising scrap tire rubber granules, reduces vertical stress within the track substructure. Laboratory investigations on an innovative composite material consisting of soil, scrap rubber granules, and polyurethane demonstrate its potential to enhance track performance. Findings from two-dimensional (2D) FE analyses conducted on pile-supported railway embankments highlight an enhanced transfer of load to the pile head following the installation of a geogrid layer at the embankment base. Finally, the results from the analytical approach indicate a reduction in track settlement and a decrease in the track geometry degradation rate on reinforcing the ballast layer with 3D cellular geoinclusion. The novelty of this study lies in the comprehensive assessment of the innovative composite material under drained and cyclic loading conditions, the investigation of the influence of train loading on geosynthetic tension and the load transfer mechanism in railway embankments, and the development of an innovative computational methodology capable of assessing the effectiveness of 3D cellular inclusions in improving the ballasted railway track performance. The findings from this article underscore the effectiveness of these sustainable approaches in mitigating the challenges posed by increased loads on railway tracks, providing valuable insights for the ongoing efforts to optimize railway transportation infrastructure.

Energy Recovery Efficiency of Integrating Anaerobic Co-Digestion of Pig Slurry and Feedlot Cattle Manure and Hydrothermal Carbonization of Anaerobic Sludge Cake

Hydrothermal carbonization (HTC) is a technology designed to improve the efficiency of bioenergy recovery by subjecting biomass to high-temperature and high-pressure conditions. By integrating this technical feature with anaerobic digestion (AD), enhanced energy recovery efficiency is achieved in treating anaerobic digestate (AD-T). The study investigates enhancing bioenergy recovery efficiency through an integrated process, combining AD of livestock manure and HTC. The primary objective is to improve the energy conversion efficiency of biomass characterized by varying solid contents and chemical compositions. Shortening the hydraulic retention time (HRT) in AD of livestock manure resulted in decreased degradation rate efficiency within the AD-T. This led to increased solid material accumulation, which was crucial for the subsequent HTC reaction. The HTC reaction exhibited its maximum bioenergy recovery at 160 °C. The input energy of the livestock manure, obtained by mixing pig slurry and feedlot cattle manure in a 1:1 (w/w) ratio, was 171,167 MJ/day. Under different HRT conditions (40, 30, and 20 days), recoverable energy from AD of livestock manure ranged from 60,336 to 68,517 MJ/ton. Integration of HTC increased net bioenergy recovery to 106,493 to 130,491 MJ/day under corresponding HRT conditions, highlighting the potential of integrating HTC with AD from livestock manure for enhanced bioenergy recovery efficiency.

Application and Properties of Polyglycolic Acid as a Degradation Agent in MPU/HNBR Degradable Elastomer Composites for Dissolvable Frac Plugs.

In this research, fully degradable elastomeric sealing materials were developed to enhance the environmental sustainability of oil and gas extraction. The modification of millable polyurethane rubber (MPU) with polyglycolic acid/hydrogenated nitrile butadiene rubber (PGA/HNBR) led to the synthesis of PGA@MPU/HNBR composite materials. The impact of varying monomer quantities on the mechanical properties, degradation behavior, degradation mechanisms, and thermal stability of these materials was investigated. Our findings illustrate that an increasing proportion of HNBR in the PGA@MPU/HNBR composite materials resulted in a decreased degradation rate. Simultaneously, higher HNBR content improved the thermal stability of the materials, while the inclusion of PGA reduced material hardness, rendering the composites more susceptible to swelling. At an HNBR content of 40 phr, MPU at 60 phr, and PGA at 6 phr, the composite material demonstrated the highest retention of mechanical properties at 31.3% following 168 h of hydrolysis at 100 °C. The degradation of the composite materials in 100 °C water primarily resulted from the hydrolysis of MPU's ester groups, with HNBR remaining unaffected.

Second phase Cu2O boosted photocatalytic activity of fluorine doped CuO nanoparticles.

The photocatalytic activity of fluorine (F) doped CuO nanoparticles (NPs) prepared employing modified sol-gel process was investigated here in this study. Structural and elemental characterization using XRD and XPS data confirmed successful incorporation of F as dopant. F doping led to lattice distortion and reduced crystallinity with smaller crystallite size while promoting the emergence of Cu2O as the second phase. Morphological analysis showed irregularly shaped, fused particles with a decreasing particle size trend upon doping. Addition of hydrogen peroxide generated hydroxyl radicals (OH˙) under ultra-violet (UV) light, which effectively degrades pollutants by facilitating the photocatalytic kinetics. Photocatalytic activity of all the nanoparticles was examined against Rhodamine B (Rh B) dye and most efficient degradation (97.78%) was observed for 3 mol% F dopant concentration. The emergence of Cu2O phase for doping beyond 1 mol% F doped CuO might be the prime reason to enhance its degradation performance. Conversely, 5 mol% doping caused notable phase changes and decreased degradation rate (88.05%) due to increased recombination rate in presence of metallic copper. The ability of F doped CuO nanoparticles to disintegrate organic contaminants by producing reactive oxygen species when exposed to UV light suggests their potential effectiveness in applications such as dye degradation, water purification, and environmental sustainability.

Biomimetic amniotic/silicone-based bilayer membrane for corneal tissue engineering

Amniotic membrane (AM) is an effective and widely used dressing in ocular injuries to reconstruct the cornea. Due to its low mechanical strength, high biodegradation rate, and difficult handling, its usage in medical interventions remains challenging. In this study, decellularized AM was covered with an ultrathin layer of Polydimethylsiloxane (PDMS) through a spinning method, which in turn resulted in an ultrathin (less than 80 µm in thickness) bilayer corneal wound dressing membrane with improved mechanical behavior and transparency. The biomechanical, biological, and antibacterial properties of the bilayer membranes were measured both in vitro and in vivo. The optimized microsized membrane was applied on a corneal defect wound created in a rabbit model to evaluate the corneal healing. The results demonstrated a significant decrease in degradation rate, improved mechanical properties, and AM/PDMS transparency compared with AM.Thecorneal transparency improved until 21 days post-surgery inAM/PDMS group. Histological evaluations revealed that AM/PDMS had better epithelial delaminated cell morphology. The results of the RT-PCR showed a significant increase in MMP9, a significant decrease in Col1A1, TGF-β1, TNF-α and IL-6 in both AM and AM/PDMS compared with control wounds. This study suggessts AM/PDMS membrane as an excellent corneal wound dressing.

Effect of sodium dodecyl sulfate on preferential degradation of naphthalene by thermally activated persulfate: Implications for soil flushing solution reuse

Various flushing solutions that contain hydrophobic organic compounds and surfactants are generated during surfactant-enhanced soil flushing processes. How to effectively remove the target pollutants while minimizing the degradation of surfactants for reuse of the flushing solutions has become a major problem. A series of batch experiments were conducted to investigate the preferential degradation mechanisms of naphthalene by sodium dodecyl sulfate (SDS) as well as the effect of SDS concentration on the degradation efficiency using a competitive kinetic method. In addition, the effects of persulfate (PS) dosage, temperature, and pH on the degradation efficiency of naphthalene were also studied, and a prediction model based on response surface methodology (RSM) was built to optimize the preferential degradation of naphthalene. One-dimensional column flushing experiments were performed to evaluate the feasibility of reusing soil flushing solutions at the predicted PS dosage. Results show that: (i) SDS inhibited naphthalene degradation owing to competitive oxidation and micellar protection, with a decreasing degradation rate constant as SDS concentration increased. However, naphthalene was still degraded by reactive oxygen species (ROS) at a higher rate than SDS, indicating the preferential degradation of naphthalene. When the concentration of SDS increased from 5 to 10 times of critical micelle concentration (CMC; 8.2 mM), the ratio for rate constants of naphthalene to SDS (kNAP/kSDS) decreased significantly from 31.61 to 3.38, illustrating the obvious effect of SDS concentration on preferential degradation of naphthalene; (ii) The formation of single-chambered vesicles with a higher thermodynamic stability was observed at 10 CMC, compared to the spherical micelles formed at 5 CMC. The accessibility of naphthalene to ROS was greatly reduced at 10 CMC, resulting in a significant reduction in kNAP/kSDS value. Moreover, the method in which ROS attacked naphthalene in surfactant micelles varied with SDS concentration, which also impacted the preferential degradation of naphthalene; (iii) Under the optimal PS dosage predicted by the RSM model, a good reusability of SDS was observed in the soil flushing solutions after thermally activated PS oxidation, with a significant reduction on the toxic risk of soil after flushing.

PSIII-24 Effect of Curing Extent on Red Clover Hay and Silage in Situ Degradability Kinetics in Dairy Cattle

Abstract This objective was to evaluate the effects of insufficient (WET) or ample (CUR) curing on red clover silage (29.4 and 45.3% DM, respectively) and hay (65.1 and 89.1% DM, respectively) ruminal degradation. The red clover field was divided into 5 blocks and each block was divided into 2 plots and then assigned randomly to silage and hay. Hay was packed into mini-bales (~500 fresh g; ~232 kg DM/m3) and silage into mini-silos (19.5 L; ~214 kg DM/m3). Measurements were taken once storage processes had stabilized for hay and silage (50 and 78 d, respectively). Samples were ground to pass 4-mm screen and weighed (5 g DM) into 10 x 20 cm ANKOM R1020 in situ bags. Bags were hooked to a rope, placed in the ventral sac of the rumen of 2 dairy cows for 0, 3, 6, 12, 24, 48, 72, and 96 h. All bags were removed simultaneously, washed, dried, and weighed. This procedure was conducted separately for each block. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (curing extents) x 2 (storage methods) factorial. Differences were declared at P ≤ 0.05. Discrete lag times were higher for WET than CUR (0.23 vs. 0 ± 0.08 h, respectively). The potentially degradable fraction was greater in hay than in silage (50.2 vs. 45.1 ± 1.32% of DM, respectively). Moreover, WET had a greater potentially degradable fraction than CUR (49.6 vs. 45.7 ± 1.32% of DM, respectively). The degradation rate was less in hay than silage (5 vs. 8 ± 0.4%/h, respectively). The WET treatment had a decreased degradation rate than CUR (5 vs. 7, respectively). The undegradable fraction was not different between WET and CUR hay (x̅ = 23.3 ± 1.13% of DM). In contrast, WET silage had a decreased undegradable fraction than CUR silage (17.1 vs. 20, respectively). In conclusion, haymaking increased the potentially degradable fraction relative to ensiling but reduced the rate of digestion. For both storage methods, curing reduced the potentially degradable fraction but increased the rate of digestion.

Preparation of CuO loaded cation exchange resin composites and its degradation of polyacrylamide aqueous solution

Macroporous cation exchange resins (CER) were used as carriers, and CuO loaded cation exchange resin composites was successfully prepared under thermostatic oscillation and hydrothermal conditions. The results showed that the as-prepared composites exhibited obvious shell-core structure. The different amounts of NaOH affected the micro morphology of CuO on the surface and in the internal pores of the resin, and also affected the percentage content of Cu element. XRD characterization clearly revealed that the products were monoclinic crystal system CuO species with a grain size of about 16 nm. The highest degradation rate of polyacrylamide (PAM) by CuO@IER-1g reached 81.94%, after 6 cycles CuO@CER-1g has still good photocatalytic activity, and the decrease in degradation rate was the combined effect from the adsorption of ion exchange resins and the electron-hole pairs formed by CuO and a series of free radical transfer reactions under ultraviolet light. This study has important theoretical basis and practical significance for enriching ion exchange theory, developing the photocatalytic industry, and purifying the environment.

New Triple Metallic Carbonated Hydroxyapatite for Stone Surface Preservation

This paper presents the synthesis of the triple substituted carbonated hydroxyapatite with magnesium, strontium and zinc (Mg-Sr-Zn-CHAp), as well as its structural, morphological and compositional characterization. The analytical techniques used (WDXRF, XRD and FTIR) highlighted, on the one hand, the B form for the apatite structure, as well as the presence of the three metal ions in the apatite structure, on the other hand (small shifts of 1120–900 cm−1 and 500–600 cm−1 absorption peaks due to the metals incorporated into the CHAp structure). The ratio between the metallic ions that substitute calcium and Ca2+, and phosphorus is increased, the value being 2.11 in comparison with CHAp and pure hydroxyapatite. Also, by using imaging techniques such as optical microscopy and SEM, spherical nanometric particles (between 150 and 250 nm) with a large surface area and large pores (6 m2/g surface area, pores with 6.903 nm diameters and 0.01035 cm3/g medium volume, determined by nitrogen adsorption/desorption analysis) and a pronounced tendency of agglomeration was highlighted. Also, the triple substituted carbonated hydroxyapatite was tested as an inorganic consolidant by using stone specimens prepared in the laboratory. The efficiency of Mg-Sr-Zn-CHAp in the consolidation processes was demonstrated by specific tests in the field: water absorption, peeling, freeze–thaw behavior, chromatic parameters as well as mechanical strength. All these tests presented conclusive values for the use of this consolidant in the consolidation procedures of stone surfaces (lower water absorption, increased mechanical strength, higher consolidation percent, decreased degradation rate by freeze–thaw, no significant color changes).

Physical, mechanical, and biological performance of chitosan-based nanocomposite coating deposited on the polycaprolactone-based 3D printed scaffold: Potential application in bone tissue engineering

Recently, coating on composite scaffolds has attracted many researchers' attention to improve scaffolds' properties. In this research, a 3D printed scaffold was fabricated from polycaprolactone (PCL)/magnetic mesoporous bioactive glass (MMBG)/alumina nanowire (Al2O3, Optimal percentage 5 %) (PMA) and then coated with chitosan (Cs)/multi-walled carbon nanotubes (MWCNTs) by an immersion coating method. Structural analyses such as XRD and ATR-FTIR confirmed the presence of Cs and MWCNTs in the coated scaffolds. The SEM results of the coated scaffolds showed homogeneous three-dimensional structures with interconnected pores compared to the uncoated scaffolds. The coated scaffolds exhibited an increase in compression strength (up to 16.1 MPa) and compressive modulus (up to 40.83 MPa), improved surface hydrophilicity (up to 32.69°), and decrease in degradation rate (68 % remaining weight) compared to the uncoated scaffolds. The increase in apatite formation in the scaffold coated with Cs/MWCNTs was confirmed by SEM, EDAX, and XRD tests. Coating the PMA scaffold with Cs/MWCNTs leads to the viability and proliferation of MG-63 cells and more secretion of alkaline phosphatase and Ca activity, which can be introduced as a suitable candidate for use in bone tissue engineering.

Performance, electrochemical process analysis and degradation of gadolinium doped ceria as fuel electrode material for solid oxide electrolysis cells

One major challenge that has to be solved to enable a market entry of solid oxide electrolysis cells (SOECs) technology is the poor degradation behaviour caused by nickel agglomeration and migration in the state-of-the-art fuel electrodes. Novel fuel electrode materials that either suppress the nickel migration or even nickel-free electrodes could lead to a decrease in degradation rates. In this work, single cells based on the mixed ionic electronic conducting (MIEC) gadolinium doped ceria (GDC), acting as single-phase fuel electrode, were prepared. The cell performance was investigated by current density-voltage characteristics (jV) for steam and co-electrolysis conditions at various operating temperatures. Furthermore, electrochemical processes occurring in the single cells were analysed using electrochemical impedance spectroscopy (EIS), distribution of relaxation times (DRT) analysis and equivalent circuit model (ECM) fitting. Current densities of –914 and –969 mA‧cm−2, respectively, at 1.5 V and 900 °C operating temperature for steam and co-electrolysis were obtained, which corresponds to about 70% of the current density achieved in similar produced Ni-GDC fuel electrode cells. In addition, a long-term stability test was carried out during steam electrolysis (50% H2O + 50% H2) at 900 °C with a constant current load of –0.5 A‧cm−2 for 1070 h. In comparison to Ni-YSZ and Ni-GDC fuel electrode single cells reported in the literature, a significantly lower degradation rate of 112 mV‧kh−1 was observed. The electrochemical investigations and post-test analyses using SEM-EDX reveal that the GDC fuel electrode does not contribute significantly to the degradation, while the LSCF oxygen electrode is the major contributor to the cells’ degradation.

Experimental study on the treatment of dye wastewater by plasma coupled biotechnology

In this experiment, a gas-liquid two-phase discharge water treatment inverse device was designed independently to treat the actual workshop intermediate dye wastewater from a chemical plant. Firstly, the effects of initial concentration of wastewater, initial pH, circulation flow rate of solution, content of Fe2+, content of H2O2, and addition of tert-butanol on the organic removal rate and decolorization rate of dye wastewater treatment were investigated. The results showed that Fe2+ and tert-butanol would react with the active particles (H2O2, ·OH) and inhibit the degradation of the dye wastewater, resulting in the decrease of both organic matter degradation rate and decolorization rate. The experimentally degraded dye wastewater mainly contained benzoic acid and its derivatives in addition to dye molecules, thus the degradation mechanism of benzoic acid was mainly analyzed. Then, the actual dye wastewater treated by low-temperature plasma was combined with the traditional biological treatment technology. The biochemical properties of the wastewater treated by low-temperature plasma technology were greatly improved, and the B/C was increased from the initial 0.17 to 0.33. The effluent after the combined biological method could meet the effluent discharge standard, and the final CODcr reached 198mg/L, BOD5 reached 65mg/L, and pH and chromaticity reached 6.39 and 50, respectively.