Search Results (121)

Redox flow batteries (RFBs) are an emerging class of large-scale energy storage devices, yet the commercial benchmark—vanadium redox flow batteries (VRFBs)—is highly constrained by a modest open-circuit potential (1.26 V) while posing an expensive and volatile material procurement costs. This review focuses on recent progress in diversifying redox-active species to overcome these limits, highlighting chemistries that increase overall cell voltage, energy density, and efficiency while maintaining long cycle life and safety. The study dwells deeper into manganese-based systems (e.g., Mn/Ti, Mn/V, Mn/S, M/Zn) that leverage Mn’s high positive potential while addressing Mn(III) disproportionation reactions; iron-based hybrids (Fe/Cr, Fe/Zn, Fe/Pb, Fe/V, Fe/S, Fe/Cd) that exploit the low cost, and its abundance, along with membrane and electrolyte strategies to prevent the potential issue involving crossover; cerium-anchored catholytes (Ce/Pb, V/Ce, Eu/Ce, Ce/S, Ce/Zn) that deliver high operational voltage by implementing an acid-base media, along with selective zeolite membranes; and halide systems (Zn–I, Zn–Br, Sn–Br, polysulfide–bromine/iodide) that combine fast redox kinetics and high solubility with advances such as carbon-coated membranes, bromine complexation, and ambipolar electrolytes. Across these various families of RFBs, the review highlights the modifications made to the flow-fields, membranes, and electrodes by utilizing a zero-gap serpentine flow field, sulfonated poly(ether ether ketone) (SPEEK) membranes, carbon-modified and zeolite separators, electrolyte additives to enhance the voltage (VE%), and thereby energy (EE%) efficiency, while reducing the overall system cost. These modifications to the existing RFB technology offer a promising alternative to traditional approaches, paving the way for improved performance and widespread adoption of RFB technology in large-scale grid-based energy storage solutions. Full article

This paper presents the general framework of the problem and the basis for the proposed idea, which lies in the design of a new extrusion nozzle for fused-deposition 3D printing, featuring a variable orifice that enables adaptive extrusion control to improve printing properties such as material efficiency, printing speed, and localized control of mechanical properties. The working principle is controlled compression, via a linear actuator, of a silicone sleeve installed inside a metal jacket. Constrained by the metal jacket, the diameter of the silicone sleeve’s through-hole decreases with increasing compression. Three experiments were carried out to verify the functionality of the new nozzle design. The first two explored how the size of the nozzle orifice changes with movement of the linear actuator and the resulting silicone sleeve compression and decompression. In the third experiment, three sample parts were printed to demonstrate how the variable-orifice-size nozzle extruded PLA. The orifice diameter was set to $1.4$ mm for the first condition, $0.7$ mm for the second condition, and, in the third experiment, the first two conditions were combined. The orifice diameter was set to $1.4$ mm for the first half of the object and then abruptly reduced to $0.7$ mm for the second half. The prototype variable-orifice-size nozzle system demonstrated the potential of adaptive extrusion control for improved material efficiencies, faster printing times, and localized control of mechanical properties. However, it also revealed hysteresis of the silicone sleeve, a problem that must be addressed. Full article

In this study, the neutron and gamma radiation-shielding properties of serpentinites from the Guleman ophiolite complex were investigated, and results were evaluated in comparison with rare earth element (REE) content. The linear and mass attenuation coefficients (LAC and MAC), half-value layer (HVL), mean free path (MFP), and effective atomic numbers (Z_eff) of serpentinite samples were experimentally measured in the energy range of 80.99–383.85 keV. Theoretical MAC values were calculated. Additionally, fast neutron removal cross-sections, as well as thermal and fast neutron macroscopic cross-sections, were theoretically determined. The absorbed equivalent dose rates of serpentinite samples were also measured. The radiation protection efficiency (RPE) for gamma rays and neutrons were determined. It was observed that the presence of rare earth elements within serpentinite structure has a significant impact on thermal neutron cross-sections, while crystalline water content (LOI) plays an influential role in fast neutron cross-sections. Moreover, it has been observed that the concentration of gadolinium exerts a more substantial influence on the macroscopic cross-sections of thermal neutrons than on those of fast neutrons. The research results reveal the mineralogical, geochemical, morphological and radiation-shielding properties of serpentinite rocks contribute significantly to new visions for the use of this naturally occurring rock as a geological repository for nuclear waste or as a wall-covering material in radiotherapy centers and nuclear facilities instead of concrete. Full article

This study presents a hybrid computational investigation into the radiation shielding behavior of Fe-enriched Al-based alloys (Al-Fe-Mo-Si-Zr) for potential use in nuclear applications. Four alloy compositions with varying Fe contents (7.21, 6.35, 5.47, and 4.58 wt%) were analyzed using a combination of Monte Carlo simulations, machine learning (ML) predictions based on multilayer perceptrons (MLPs), EpiXS, and SRIM-based charged particle transport modeling. Key photon interaction parameters—including mass attenuation coefficient (MAC), half-value layer (HVL), buildup factors, and effective atomic number (Z_eff)—were calculated across a wide energy range (0.015–15 MeV). Results showed that the 7.21Fe alloy exhibited a maximum MAC of 12 cm²/g at low energies and an HVL of 0.19 cm at 0.02 MeV, indicating improved gamma attenuation with increasing Fe content. The ML model accurately predicted MAC values in agreement with Monte Carlo and XCOM data, validating the applicability of AI-assisted modeling in material evaluation. SRIM calculations demonstrated enhanced charged particle shielding: the projected range of 10 MeV protons decreased from ~55 µm (low Fe) to ~50 µm (high Fe), while alpha particle penetration reduced accordingly. In terms of fast neutron attenuation, the 7.21Fe alloy reached a maximum removal cross-section (Σ_R) of 0.08164 cm⁻¹, showing performance comparable to conventional materials like concrete. Overall, the results confirm that Fe-rich Al-based alloys offer a desirable balance of lightweight design, structural stability, and dual-function radiation shielding, making them strong candidates for next-generation protective systems in high-radiation environments. Full article

This study employs simulation tools to design and evaluate lightweight, lead-free polymer composites incorporating polytetrafluoroethylene (PTFE), polyethylene (PE), and polyetherimide (PEI) for gamma radiation shielding in nuclear medicine. Targeting clinically relevant photon energies from Tc-99m (140 keV), I-131 (364 keV), and Cs-137 (662 keV), composites’ structural and shielding performance with Bi₂O₃ and WO₃ was assessed using XCOM and Phy-X/PSD. PEI emerged as the most suitable polymer for load-bearing and thermally exposed applications, offering superior mechanical stability and dimensional integrity. Bi₂O₃-WO₃ fillers for Tc-99m achieved a ~7000-fold increase in MAC, I-131 ~2063-fold, and Cs-137 ~1370-fold compared to PbO₂. The PEI-75Bi₂O₃-25WO₃ achieved a ~21-fold reduction in half-value layer (HVL) compared to lead for Tc-99m. For higher-energy isotopes of I-131 and Cs-137, HVL reductions of ~0.44-fold and ~0.08-fold, respectively, were achieved. The results demonstrate that high-Z dual filler polymer composites have an equal or enhanced attenuation properties to lead-based shielding, whilst also enhancing the polymer composites’ mechanical and thermal characteristics. As the use of ionizing radiation increases, so does the potential risks; high-Z dual filler polymer composites provide a sustainable, lightweight, non-toxic alternative to conventional lead shielding. Full article

The optical and radiation shielding of PVA have been enhanced through embedding with ZnO/CuO/SWCNT (ZCS) nanocomposites. ZCS polymeric nanocomposites (PNCs) were prepared with the solution casting method. Scanning electron, optical microscopy and FT-IR procedures were performed to examine the surfaces’ morphology and structures’ modifications. UV–visible measurements were carried out to investigate the linear/nonlinear optical properties. The optical investigations show significant alterations in the optical parameters of PVA due to ZCS embedding. The UV–visible analysis shows that the optical parameters, including the transmittance, energy bandgap, refractive index, dielectric constants and optical conductivity of PVA, are tuned through ZCS embedding. The direct and indirect bandgap of PVA shrank from 5.42 eV and 4.99 eV (neat PVA) to 3.20 eV and 2.26 eV (10 wt.% ZCS PNCs). The nonlinear optical (NLO) constants (first order susceptibility (χ⁽¹⁾), third susceptibility (χ⁽³⁾) and refractive index (n₂)) of PVA were improved. Phy-X/PSD software was used to investigate the radiation shielding parameters of all samples. The linear attenuation coefficient (LAC), mean free path (MFP), half value layer (HVL), tenth value layer (TVL) and effective atomic number (Z_eff) of PVA were enhanced through ZCS embedding. It is found that the mass attenuation coefficient (MAC) of the neat PVA increased from 1.14 cm²/g to 7.96 cm²/g at 0.015 MeV. The HVL of PVA decreased from 30.2 cm to 20.6 cm, the TVL decreased from 100.3 cm to 68.5 cm and the MFP decreased from 43.6 cm to 29.8 cm upon embedding 10 wt.% of ZCS NCs at 15 MeV. The samples’ exposure buildup factor (EBF) and energy absorption buildup factor (EABF) in the photon energy range from 0.015 MeV to 15 MeV at 0.5 to 40 MFP values. This study proves that ZCS PNCs are advantageous for applications in optical and radiation shielding fields. Full article

Metabolic bone disease (MBD) is clinically characterized by bone deformities and is associated with vitamin D3 deficiency in diurnal animals. However, the pathogenesis and etiology of this condition in flying foxes, considered nocturnal animals, are poorly understood. Therefore, we conducted a survey aimed at various zoological parks housing flying foxes to elucidate the pathogenesis and etiology of MBD in these animals. Our results indicate that vitamin D3 may play a role in preventing metabolic bone disease in flying foxes due to its involvement in calcium absorption. However, these nocturnal animals seem to obtain vitamin D3 primarily through dietary sources in contrast to the cutaneous absorption described in diurnal species. Additionally, our results suggest that an appropriate diet for this species, including fruits, green vegetables, and other protein sources such as animal products and mineral supplementation, could contribute to preventing metabolic bone disease. Full article

This study explores what unaccompanied refugee minors (URMs) emphasise as important to (re)create a sense of home in foster care over time. Through a longitudinal design consisting of semi-structured, photo-elicitation interviews and by drawing on the concept of homing, we clustered young people’s experiences into three intertwined aspects that contribute to (re)creating a sense of home in foster care: security, familiarity, and autonomy. The study highlights the importance of the emotional, relational, and material resources that young people may access through familial relationships (in foster care), which seem to be an essential part of (re)creating a sense of home. Our findings unpack how URMs in foster care are active agents in doing and becoming home—not just being at home—highlighting their participation and continuous navigation of belonging in daily life. Moreover, our analysis indicates that URMs (re)creating a sense of home in foster care is a dynamic and temporal process between their past experiences, present circumstances, and future aspirations. It is essential for child welfare workers and foster parents to be aware of and support URMs’ connections to their heritage background, birth families, and foster parents during transitions, as well as their individual needs. Findings from this study nuance existing research on what contributes to a supportive foster care environment for URMs, specifically how foster parents can facilitate URMs’ sense of home over time. Yet, our findings also highlight the need for further research on how to better support continuity in foster care for URMs, particularly regarding the role and meaning of cultural, religious, and linguistic belonging. Full article

Entecavir (ETV) may have limited antiviral efficacy in chronic hepatitis B (CHB) patients with a high baseline viral load, especially in cases of partial virologic response (PVR). This study evaluated the outcomes of prolonged ETV monotherapy, given the lack of clear evidence favoring continuation or combination therapy in such scenarios. We included 188 treatment-naïve patients on ETV 0.5 mg and compared antiviral responses between high viral load (HVL, ≥7 log10 IU/mL) and non-HVL groups for over up to 120 months in this study. Compared to the non-HVL group, the HVL group exhibited a lower cumulative virologic response (VR, <20 IU/mL) during the 10-year therapy period (p < 0.01). Antiviral resistance to entecavir (rtS202G + rtM204V + rtL180M) developed in three out of 90 patients in the HVL group. Patients with complete response at 6 months had a 100% likelihood of achieving VR, while 83.9% of patients with PVR at 6 months achieved VR by month 120 (p < 0.01). Multivariate analysis revealed that baseline HVL was a significant predictor of long-term VR at 120 months. In conclusion, CHB patients with baseline HVL and PVR at 6 months are prone to ETV resistance and inadequate response, warranting a modification in treatment strategy. Full article

This study explores the physical, radiation shielding, optical, and photoluminescent properties of PbO₂-SiO₂-based glass systems. Traditional radiation shielding materials, like lead and concrete, face challenges due to toxicity and weight. Glass materials provide an alternative, offering transparency and efficiency. Four glass systems were analyzed: PbO₂-SiO₂ (PS), PbO₂-SiO₂-CeO₂ (PSC), PbO₂-SiO₂-Eu₂O₃ (PSE), and PbO₂-SiO₂-Yb₂O₃ (PSY). The results show that rare earth elements densify the glass network, thereby enhancing radiation attenuation properties, quantified through parameters like the linear attenuation coefficient (μ), the half-value layer (HVL), and the mean free path (MFP). The PSY system exhibited the best shielding properties, demonstrating its potential for use in gamma ray shielding. Samples PS0–PS3 revealed semiconducting behavior and may be considered a promising host matrix for solar cells and w-LED applications. Full article

This research assess the role of traditional food producers’ activities in fostering local sustainability in Poland. The study was carried out at the turn of 2021 and 2022, involving a sample of 70 traditional food producers. It utilized semi-structured interviews, which included two categories of questions: the characteristics of traditional food producers and the significance of their operational goals. Given the unique nature of traditional food in Poland, producers can be categorized into three groups, based on their connection to tradition: local, regional, and national. Differences among these groups were analyzed using a series of t-tests. The findings indicate that in the hierarchy of goals for traditional food producers, socio-cultural objectives take precedence, followed by business goals, while goals related to food safety, quality, and environmental responsibility rank as the least important, with significant differences noted. Producers associated with local traditions, predominantly consisting of family businesses, show the least interest in achieving food safety, quality, and environmental responsibility objectives. While traditional food producers in Poland are adopting pro-ecological practices, these are primarily driven by business considerations and market demands. Full article

Ionizing radiation plays an essential role across various fields but also poses significant health risks, requiring effective shielding solutions. This study focuses on the photon shielding properties of PbO-reinforced composites, specifically PbO-0, PbO-2, PbO-4, PbO-6, PbO-8, and PbO-10, through experimental measurements of photon energies ranging from 59.5 keV to 1408.0 keV. The measurements were taken using an HPGe detector. Experimental results were compared to theoretical calculations. Among the tested composites, PbO-10, which contains the highest concentration of lead oxide (PbO), provided the most effective radiation shielding. This sample demonstrated superior mass and linear attenuation coefficients, offering excellent protection at low photon energies. Furthermore, PbO-10 exhibited the lowest half-value layer (HVL) and tenth-value layer (TVL) values, indicating its efficiency in reducing radiation intensity with thinner material layers. It was determined that the experimental TVL results for PbO-O, PbO-2, PbO-4, PbO-6, PbO-8, and PbO-10 at 59.5 keV photon energy were 9.95, 5.98, 4.77, 3.67, 3.22, and 2.71 cm, respectively. With these outstanding attenuation capabilities, PbO-10 is deemed highly suitable for use in medical, industrial, and radiation-heavy environments. In summary, this research emphasizes the effectiveness of PbO-reinforced composites in gamma-ray shielding, with PbO-10 emerging as the top performer, demonstrating great potential for applications that require durable and efficient radiation protection. Full article

During COVID-19, the Norwegian Government provided compensation to amend firms’ decreased revenues, yet it should be neutral and tailored to losses only. However, firm resources or institutional factors may have influenced the compensation, which we study here. Survey data showed a high probability of compensation among large firms, although they were not hit particularly hard by COVID-19. Also, compensation was prevalent for firms in the hospitality, tourism, and culture industry, and a likely explanation is that they were hit hard. However, their probability of compensation was prevalent compared to firms in other industries, regardless of revenue losses. We assume that large firms’ compensation was due to their resources to apply for funding successfully, while institutional factors explained the compensation for firms in the hospitality, tourism, and culture industry. Full article

The cerebral small vessel disease (cSVD) is one of the main causes of vascular and mixed cognitive impairment (CI), and it is associated, in particular, with brain ageing. An understanding of structural tissue changes in an intact cerebral white matter in cSVD might allow one to develop the sensitive biomarkers for early diagnosis and monitoring of disease progression. Purpose of the study: to evaluate microstructural changes in the corpus callosum (CC) using diffusion MRI (D-MRI) approaches in cSVD patients with different severity of CI and reveal the most sensitive correlations of diffusion metrics with CI. Methods: the study included 166 cSVD patients (51.8% women; 60.4 ± 7.6 years) and 44 healthy volunteers (65.9% women; 59.6 ± 6.8 years). All subjects underwent D-MRI (3T) with signal (diffusion tensor and kurtosis) and biophysical (neurite orientation dispersion and density imaging, NODDI, white matter tract integrity, WMTI, multicompartment spherical mean technique, MC-SMT) modeling in three CC segments as well as a neuropsychological assessment. Results: in cSVD patients, microstructural changes were found in all CC segments already at the subjective CI stage, which was found to worsen into mild CI and dementia. More pronounced changes were observed in the forceps minor. Among the signal models FA, MD, MK, RD, and RK, as well as among the biophysical models, MC-SMT (EMD, ETR) and WMTI (AWF) metrics exhibited the largest area under the curve (>0.85), characterizing the loss of microstructural integrity, the severity of potential demyelination, and the proportion of intra-axonal water, respectively. Conclusion: the study reveals the relevance of advanced D-MRI approaches for the assessment of brain tissue changes in cSVD. The identified diffusion biomarkers could be used for the clarification and observation of CI progression. Full article

Live attenuated influenza vaccines (LAIV) typically induce a poor hemagglutination inhibition (HI) response, which is the standard correlate of protection for inactivated influenza vaccines. The significance of the HI response is complicated because the LAIV vaccine primarily induces the local mucosal immune system, while the HI assay measures the circulating serum antibody response. However, age and pre-existing immunity have been identified as important factors affecting LAIV immunogenicity. This study aimed to extend our understanding of LAIV-induced immunity, particularly, the impact age and pre-existing immunity have on eliciting functional and neutralising antibody responses in paediatric and adult populations vaccinated with LAIV. Thirty-one children and 26 adults were immunized with the trivalent LAIV during the 2013–2014 influenza season in Norway. Children under 9 years received a second dose of LAIV 28 days after the first dose. Blood samples were collected pre- and post-vaccination. HI, microneutralization (MN) and enzyme-linked lectin assay for neuraminidase (NA) antibodies were measured against the vaccine strains. IgG antibody avidity against hemagglutinin (HA) and NA proteins from the vaccine strains was also assessed. Significant correlations were observed between HI and MN responses to A/California/7/2009 (A/H1N1)pdm09-like strain and B/Massachusetts/2/2012-like strain, suggesting that MN is a potential immunological correlate for LAIV. However, the relationship between recipient age (or priming status) and serological response varied between vaccine strains. There was a notable increase in HI and MN responses in all cohorts except naive children against the H1N1 strain, where most recipients had responses below the protective antibody threshold. NAI responses were generally weak in naive children against all vaccine strains compared with adults or antigen-primed children. Post-vaccination antibody avidity increased only in primed children below nine years of age against the A/H1N1 strain. Overall, our findings indicate that LAIV elicits functional and neutralizing antibody responses in both naive and antigen experienced cohorts, however, the magnitude and kinetics of the response varies between vaccine strains. Full article