Increase In Peak Intensity Research Articles

Encapsulation Engineering of Sulfur into Magnesium Oxide for High Energy Density Li–S Batteries

This study addresses the persistent challenge of polysulfide dissolution in lithium–sulfur (Li–S) batteries by introducing magnesium oxide (MgO) nanoparticles as a novel additive. MgO was integrated with sulfur using a scalable process involving solid-state melt diffusion treatment followed by planetary ball milling. XRD measurements confirmed that sulfur (S8) retains its orthorhombic crystalline structure (space group Fddd) following the MgO incorporation, with minimal peak shifts indicating slight lattice distortion, while the increased peak intensity suggests enhanced crystallinity due to MgO acting as a nucleation site. Additionally, Raman spectroscopy demonstrated sulfur’s characteristic vibrational modes consistent with group theory (point group D2h) and highlighted multiwalled carbon nanotube (MWCNT′s) D, G, and 2D bands, with a low ID/IG ratio (0.47), which indicated low defects and high crystallinity in the prepared cathode. The S–MgO composite cathode exhibited superior electrochemical behavior, with an initial discharge capacity (950 mA h g−1 at 0.1 C), significantly improved compared to pristine sulfur’s. The presence of MgO effectively mitigated the polysulfide shuttle effect by trapping polysulfides, leading to enhanced stability over 400 cycles and the consistent coulombic efficiency of over 99.5%. After 400 cycles, EDS and SEM analyses confirmed the structural integrity of the electrode, with only minor fractures and slight sulfur content loss. Electrochemical impedance spectroscopy further confirmed the enhanced performance.

Enhanced lead adsorption by eco-hydroxyapatite derived from marble sludge: Optimization and kinetic study

In this study, eco-hydroxyapatite (e-HAP) was synthesized from marble sludge via a hydrothermal process for utilization as an adsorbent in the removal of Pb2+ ions from wastewater. X-ray powder diffraction (XRD) and thermal field emission scanning electron microscope (FE-SEM) revealed that increasing the Ca/P molar ratio (CPMR) and hydrothermal temperature (HT) increased crystallinity and that the influence of HT was more apparent. An increase in crystallinity, crystal length, and peak intensity was observed following an increase in the CPMR. Adsorption studies show that when the HT was 393 K, the CPMR was 0.67, the initial Pb2+ ion concentration was 100 mg/L, the equilibrium time was 20 min, and the adsorbent dosage was 0.6 g/L. The resulting removal efficiency (99.99 %) and maximum adsorption capacity (166.65 mg/g) are both very high. Adsorption kinetics are well described using a pseudo-second-order kinetic model. This paper presents a facile and economically sustainable approach to the synthesis of e-HAP from marble sludge for use in removing of Pb2+ from wastewater.

Elucidating the Impact of Mn-Fe Substitution on The Crystal Structure of LiMn(x)Fe(1-x)PO4 Solid Solutions: A Theoretical Study

Abstract This study generated crystallography information files (CIF) to synthesize LiMn(x)Fe(1-x)PO4 solid solutions, with the Mn to Fe substitution ratio (x) ranging from 0 to 1 in 0.1 increments, guided by Vegard’s law, utilizing crystallography software. The investigation focused on how this substitution influences key structural parameters and properties within the Mn-Fe Olivine system. Specifically, it examined variations in lattice parameters, unit cell volume, cell density, and Theoretical capacity attributable to the substitution factor. Furthermore, X-ray diffraction (XRD) patterns, predicted using mathematical models through the same software, provided insights into structural changes. Notably, the XRD analysis revealed a progressive shift in peak positions and an increase in peak intensities corresponding to the substitution level. These observations were linked to the altered lattice parameters resulting from the introduction of ions with varying ionic radii, and an enhanced electron density stemming from the increased presence of Fe. This comprehensive analysis underscores the significant impact of Mn-Fe replacement on the microstructural characteristics and electron density of the olivine system, offering valuable insights into material design and optimization in the context of energy storage materials.

Assessing the potential role of arbuscular mycorrhizal fungi in improving the phytochemical content and antioxidant properties in Gomphrena globosa

Strategies to increase the secondary metabolite production, obtained from medicinal plants has been the topic of research in recent years. The symbiotic interaction between arbuscular mycorrhizal fungi and plants allows host-fungus pairings to enhance secondary metabolite synthesis. Therefore, the current study investigated the effect of inoculating two distinct AMF species discretely as well as in conjunction on the flower-derived secondary metabolites in Gomphrena globosa. The findings showed that the plants inoculated with combined treatment exhibited higher total phenolic (50.11 mg GAE/g DW), flavonoids (29.67 mg QE/g DW), saponins (122.55 mg DE/g DW), tannins (165.71 TAE/g DW) and terpenoid (8.24 mg LE/g DW) content in the methanolic extract. HPTLC examination showed the existence of kaempferol and benzoic acid with the highest amount (0.90% and 5.83% respectively) observed in the same treatment. FTIR analysis revealed functional group peaks with increased peak intensity in the combination treatment. Higher antioxidant activities such as DPPH (IC50: 401.39 µg/mL), ABTS (IC50: 71.18 µg/mL) and FRAP (8774.73 µM Fe (II) equivalent) were observed in the methanolic extract of combined treatment. To our knowledge, this is the first study on the impact of AMF inoculation on bioactive compounds and antioxidant activities in G. globosa flowers. Moreover, this study could lead to the development of novel pharmaceuticals and herbal remedies for various diseases.

The impact of plasma-activated water on the process of nickel bioremediation by Neowestiellopsis persica A1387

Cyanobacteria provide an economical, feasible, and environmentally friendly solution for heavy metal removal. In addition, plasma can facilitate the removal of heavy metals across various time frames. In this study, we applied plasma-activated water (PAW) to prepare Neowestiellopsis persica A1387 strain medium culture for 0, 10, 15, and 20 min via an Atmospheric Cold Plasma Jet device (ACPJ-17A). Nickel removal efficiency was evaluated after 48 hours of cultivation under controlled conditions at 0, 10, 30, 60, and 90 min. Further investigation was performed through FTIR, GC-MS, and XRD techniques. Statistical analysis of ANOVA and Tukey's test indicated that the samples treated for 15 min had the highest biomass dry weight, polysaccharide content, and nickel removal rate (p ≤ 0.05). The GC-MS analysis presented elevated concentrations of ethanol, 1,3-dimethylbenzene, acetic acid, 3-methylbutyl ester, aromatic chemicals, 2-methyl-1-propanol, and 3-octen-2-ol in all samples treated with plasma. The functional group analysis using the FT-IR approach showed increased peak intensities with more extended treatment periods, indicating the addition of methyl, methylene, and hydroxyl groups to the cyanobacterium cell wall. Furthermore, a peak at 468 cm⁻¹ wavelength was observed, correlating to the Ni-O stretching mode after absorption of Ni on the cyanobacterium surface. The XRD data exhibited prominent peaks in all diffraction patterns angles below 20 degrees, suggesting the presence of amorphous and non-crystalline chemical structures within the cyanobacterial structures. The peak intensity increased with longer treatment durations. The 15-min plasma treatment optimized Ni removal, but the efficiency decreased with prolonged exposure due to adverse effects such as increased reactive oxygen species (ROS) production.

Ultraviolet Light Resistance on the Properties of Polyurethane Coating with the Addition of Chlorinated Rubber

Resistance to ultraviolet light is an essential factor that coating materials must possess, especially for outdoor applications. In this study, the effect of ultraviolet light exposure on the properties of polyurethane coating with the addition of chlorinated rubber was systematically examined. The ultraviolet light exposure was performed using an ultraviolet weathering tester for 500 hours. The samples were investigated through mechanical testing, complemented by scanning electron microscope and Fourier transform infrared spectroscopy. The increase in the tensile strength and elongation at break of the polyurethane coating with the addition of chlorinated rubber was observed and compared to the pristine sample. In the beginning of the ultraviolet exposure, the tensile strength increased 486% and 114% for pristine polyurethane and polyurethane/chlorinated rubber until of 80 hours ultraviolet exposure, indicating repolymerization during the ultraviolet exposure. It was confirmed by the Fourier transform infrared spectra which showed an increase in peak intensity at wave number of 1712 cm־ˡ which indicated C=O bond in the polyurethane. The surface morphology showed micro-cracking caused by ultraviolet exposure. Finally, it was concluded that the addition of chlorinated rubber improved the resistance to ultraviolet light.

Understanding the Degradation Mechanism for NiMo Composite and Effect of Ionomer on the Activity Towards HER

Hydrogen is an essential commodity for achieving cleaner and greener energy.1,2 Due to its high gravimetric energy density, hydrogen is favored as a carbon-neutral fuel.2,3 Moreover, the electrochemical accessibility of hydrogen evolution and oxidation reactions enable hydrogen to be used as a reversible fuel, as in hydrogen battery anodes and unitized reversible fuel cells.4,5 Platinum group metals (PGMs) are excellent catalyst for hydrogen chemistry, as they exhibit negligible activation barrier for HER and HOR, but they are costly and the upstream processes for mining and purification are unsustainable.6 A promising alternative to PGM catalysts would be nonprecious transition metal alloys/composites in form of nanoparticles. These materials are more readily available and lower in cost. Nonetheless, non-precious catalysts developed to date have never met the benchmarks set by PGMs in terms of catalytic activity and stability.Our lab is continuing a long-running effort to develop and improve nickel-molybdenum (Ni–Mo) composites, which stand as one of the strongest candidates for non-PGM HER and the HOR. In prior work, we developed a method to synthesize Ni–Mo nanoparticles supported on oxidized carbon, which increases catalyst dispersion and significantly reduces losses due to interfacial resistivity.7 The catalyst composite has a core@shell structure, where in the core is mainly nickel-rich alloy and the shell is primarily molybdenum-rich oxide.Furthermore, DFT calculations suggest the addition of Mo in the catalyst subsurface weakens hydrogen binding to surface Ni sites, thus increasing the overall activity toward HER/HOR.8 In ongoing work to further develop Ni–Mo/C composites, we are focusing on catalyst degradation under storage and operating conditions. To examine catalyst durability upon extended storage, we measured activity toward hydrogen evolution progressively for a single batch of catalyst powdered retained at room temperature in an aerobic environment over 850 hours. We observed a monotonic decrease in catalytic activity culminating in a >90% decrease in activity. Post-mortem analysis via XRD showed the increased peak intensities corresponding to NiO and MoO3. We further observed that the catalyst remains active over extended periods when stored under a dry, oxygen-free atmosphere. Finally, exposing the degraded catalyst to thermal reduction increased catalytic activity. Together, these results strongly suggest aerobic oxidation as the primary degradation mechanism under shelf-storage, with straightforward mitigations steps readily available by excluding air and water. This finding further suggests that oxide component of the synthesized catalyst is not an active site for hydrogen chemistry, although we speculate that some surface oxide is beneficial for enhancing the rate of water dissociation.9 We also studied the impact of the ionomer chemistry on the catalytic activity of Ni–Mo composites for alkaline anion exchange membrane (AEM) electrolyzer applications. Surprisingly, we observed an ~80% reduction in catalytic activity for Ni–Mo composites formulated into thin film HER catalysts using poly(aryl piperidinium) (PAP) carbonate AEM ionomers relative to control samples based on Na-exchanged Nafion ionomer binders. Further work showed this result was specific to the carbonate form of the ionomer, as HER activity was fully recovered when we used halide forms of the PAP ionomer. Work is ongoing to establish the physicochemical basis of this poisoning effect.Based on these findings, we developed functional AEM electrolyzer assemblies with IrOx anodes and Ni–Mo/C cathodes, where the cathode composition was formulated based on our best results from RDE studies. These MEAs yielded electrolyzer performance properties that were indistinguishable from MEAs we tested using Pt–Ru/C cathodes that were otherwise identical in composition.8 This leads us to conclude that advanced Ni–Mo/C catalyst composites can indeed achieve performance parity with PGM catalysts on the basis of initial catalytic activity, whereas significant work remains to characterize durability under extended operating conditions.

Photocatalytic degradation of dyes using Cu3V2O8 nanorods

Synthesis of Cu3V2O8 nanorods using the hydrothermal method by varying the reaction time from 6 h to 18 h. The resulting brown powder samples underwent X-ray diffraction analysis (XRD), UV–Visible analysis, Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) analyses. XRD analysis reveals that peak intensity increases and the full width at half maximum (FWHM) decreases with increasing reaction times. The bandgap values were measured as 2.2 eV, 2.1 eV, and 2.4 eV for Cu3V2O8 nanorods synthesized with a reaction time of 6, 12, and 18 h, respectively. Morphological examination indicates well-developed nanorods at 18 h. This Cu3V2O8 nanorod showed degradation efficiencies of 69 %, 46 %, 62 %, and 73 % for Methylene Blue, Methyl Orange, Methyl Red, and Brilliant Blue dyes, respectively. This improvement in photocatalytic efficiency is attributed to Cu3V2O8 nanorods, for electrons and holes play a major role. In radical trapping experiments, it was observed that h+ radicals predominantly in the photocatalytic activity of Cu3V2O8 nanorods. Additionally, through regeneration studies, the repeatable usability of Cu3V2O8 nanorods as a catalyst was also analyzed. The results suggest that Cu3V2O8 nanorods could serve as an efficient photocatalyst for reducing organic pollutants and managing wastewater.

Reversible photoluminescence shift in imidazolium l-tartrate crystal triggered by acoustic shock waves

Abstract Imidazolium l-tartrate crystal has been grown by employing the slow evaporation technique using de-ionized water as the solvent. An impact study on the exposure of shock pulses on the surface of the material has been carried out and the influence of shock waves on its photo luminance has been investigated. In the present work, in order to carry out the experiment, a shock wave of Mach number 1.5 has been utilized which has been generated by a semi-automated Reddy Tube. Imidazolium tartrate crystal is made into a fine powder and split into four identical parts to be used for further characterization. A series of shock waves such as 25, 50, and 75 are impacted on the respective samples while keeping one of the samples as the control. The powder X-ray diffraction analysis reveals that the observed increase in peak intensity and peak shifting is due to the increase in the number of shock pulses from 25 to 75. FTIR is performed to analyze the presence of functional groups in the material before and after shock exposure. Photoluminescence measurements are also carried out for the pre- and post-shocked samples to determine the nature of optical emission with respect to various shock pulse counts. The above experimental analyzes confirm that the title sample undergoes a reversible photoluminescence shift induced by shock waves.

Non-invasive VOCs detection to monitor the gut microbiota metabolism in-vitro

This work implemented a non-invasive volatile organic compounds (VOCs) monitoring approach to study how food components are metabolised by the gut microbiota in-vitro. The fermentability of a model food matrix rich in dietary fibre (oat bran), and a pure prebiotic (inulin), added to a minimal gut medium was compared by looking at global changes in the volatilome. The substrates were incubated with a stabilised human faecal inoculum over a 24-h period, and VOCs were monitored without interfering with biological processes. The fermentation was performed in nitrogen-filled vials, with controlled temperature, and tracked by automated headspace-solid-phase microextraction coupled with gas chromatography–mass spectrometry. To understand the molecular patterns over time, we applied a multivariate longitudinal statistical framework: repeated measurements—ANOVA simultaneous component analysis. The methodology was able to discriminate the studied groups by looking at VOCs temporal profiles. The volatilome showed a time-dependency that was more distinct after 12 h. Short to medium-chain fatty acids showed increased peak intensities, mainly for oat bran and for inulin, but with different kinetics. At the same time, alcohols, aldehydes, and esters showed distinct trends with discriminatory power. The proposed approach can be applied to study the intertwined pathways of gut microbiota food components interaction in-vitro.

Investigating the Mechanical and Tribological Properties of Bio-Waste Derived Bioactive Borosilicate Glass Incorporating Strontium Oxide

Abstract The primary goal of the current research paper is to investigate the mechanical and tribological behavior of biologically active glass consisting of 31B2O3-(20-x) SiO2-24.5Na2O-24.5CaO and xSrO (in mol%). The specimens were fabricated partly using bio-waste material, in which Silica and Calcium Oxide were derived from rice husks and egg shells, respectively. The produced specimens underwent immersion in simulated bodily fluid for a week to observe their bioactive response. The bioactive behavior of the samples were examined using X-ray diffraction and FTIR spectroscopy. The compression test and hardness of the specimens were measured using universal testing machine and Vickers micro-hardness tester. Abrasion test of the specimens were performed on pin-on-disc tribometer and the worn-out surfaces were later analyzed using FESEM. The findings from FTIR and XRD analyses validated the existence of a hydroxyapatite layer on the specimen surfaces. Further, XRD data showed an increase in peak intensity after SrO was incorporated, suggesting that it played a supporting role in boosting bioactivity. The mechanical investigations indicated that the addition of SrO adversely affects both hardness and compression strength. The abrasion wear test demonstrated that BSG-5 had the highest wear rate, while BSG-0 exhibited the lowest wear rate among all specimens at a 30 mm track radius. Despite the trade-off between enhanced bioactivity and diminished mechanical strength and wear resistance, incorporating Strontium Oxide makes the glass suitable for applications prioritizing bioactivity, such as bone filling and dental contexts.

Highly reactive carbonated recycled concrete fines prepared via mechanochemical carbonation: Influence on the early performance of cement composites

Carbonated recycled concrete fines (RCF) possess the potential to serve as supplementary cementitious materials (SCMs). However, calcium carbonate (Cc) formed during traditional carbonation methods generally shows low reactivity. Moreover, the remaining calcium silicate hydrate (C-S-H) with a low Ca/Si ratio exhibits enhanced resistance to decalcification, leading to the formation of lower content of silica gels. These factors limit the reactivity and utilization of carbonated RCF in cementitious systems. In the present work, mechanochemistry was introduced into the RCF carbonation process, a technique named mechanochemical carbonation (MC), to enhance the reactivity of carbonated RCF. This study delved into the influence of MC-treated RCF (MCR) on the early performance of cement composites. The findings reveal that MCR exerted a more pronounced promotional effect on cement hydration, as demonstrated by the earlier appearance of hydration peaks for silicates and aluminates, coupled with increased peak intensity. This then resulted in a notable enhancement in early compressive strength. Specifically, with 10 wt% MCR, the compressive strength increased by approximately 19.9 % and 24.7 % at 1 d and 3 d, respectively. In comparison, samples incorporating wet carbonated RCF (WCR) demonstrated lower enhancements, with increases of only 4.5 % and 12.0 % at 1 d and 3 d, respectively. The enhanced performance of MCR can be attributed to the increased formation of nano-sized amorphous silica gels and metastable Cc. These components exhibit elevated reactivity and contribute to seeding effects, thereby promoting the overall reactivity and strength development of the cementitious system. These findings underscore the promising application potential of MC in transforming RCF into highly reactive SCMs.

Alkali rare earth double phosphates: Promising new high temperature scintillators

Alkali rare earth double phosphates were investigated for their X-ray induced scintillation. Double phosphates with stoichiometry A3Ln(PO4)2 (A = K or Rb, Ln = Eu or Tb) were synthesized via a eutectic molten salt flux yielding high quality single crystals. The systematic variation of the alkali and rare earth elements in the structure allowed for insights into the effects of the chemical composition on the scintillation output. The radioluminescence of these compositions under X-ray excitation is reported with a discussion of the variance of their luminosity as a function of both the constituent alkali and lanthanide elements. The relative luminosity of Rb3Tb(PO4)2 surpasses BGO by 30 %. The dependance of the scintillation on temperature is also investigated, including an unusual peak intensity increase for higher temperatures that can reach 1.4x of its value at room temperature for Rb3Tb(PO4)2 at 255 °C, and 2.1x for K3Tb(PO4)2 at 495 °C.

Assessing IgG4-related autoimmune pancreatitis with contrast-enhanced ultrasonography based on time-intensity curve: a single-centre prospective study.

The aim of this study was to investigate the changes in various parameters of contrast-enhanced ultrasound (CEUS) before and after treatment in patients with IgG4-related autoimmune pancreatitis (IgG4-AIP), and to identify potential indicators that can assist in evaluating disease activity. In this prospective study, we enrolled patients diagnosed with IgG4-AIP from June 2021 to November 2022. Demographic characteristics, clinical features, laboratory tests were recorded. Baseline and follow-up, conventional ultrasound and CEUS were conducted. Additionally, a region of interest (ROI) within lesions, pancreatic head, pancreatic body, and pancreatic tail was taken to draw time-intensity curves (TIC) and parameters of TIC were recorded and analysed. Seventy-three active IgG4-AIP patients were enrolled. Follow-up, a notable decrease in the size of the pancreatic lesion was observed with a reduction in the maximum diameter from 4.3 ± 2.0 cm to 1.7 ± 1.6 cm (p=0.01). The results revealed a statistically significant increase in peak intensity (PI) in the head, body, and tail regions of the pancreas (p<0.001), along with a significant rise in the area under the curve (AUC) in the tail region of the pancreas (p=0.029) after treatment compared to baseline. In contrast, no statistically significant differences were observed in other parameters of TIC. A significant increase of PI was observed in 12 patients with diffuse IgG4-AIP following treatment. Following treatment, there was a significant increase in PI in the focal area among the 12 patients with focal lesions. CEUS based on TIC holds great potential for assessing response to treatment in patients with IgG4 AIP.

S+E+O-band luminescence and enhancement in Nd3+/Tm3+/Ce3+ doped tellurite glass

A new, to our knowledge, doped combination of Nd3+, Tm3+, and Ce3+ ions was developed in tellurite glass with a fundamental composition of TeO2-ZnO-WO3-Bi2O3, and the structural, thermal, and especially near-infrared (NIR) luminescent properties in O-, E-, and S-bands were explored. The XRD pattern confirmed the amorphous nature of synthesized tellurite glass, the Raman spectrum disclosed different structural units that make up the glass network, the DSC curve confirmed good host thermal stability, while XPS measurement revealed that cerium mainly exists in the trivalent form in a glass network. Upon being pumped with an 808 nm laser, a 1.34 µm band fluorescence from Nd3+:4F3/2level→4I13/2 level transition and a 1.46 µm band fluorescence from Tm3+:3H4level→3F4 level transition were observed, which in turn formed a wide luminescence band from 1260 to 1560 nm in the tellurite glass containing both Nd3+ and Tm3+ ions owing to their spectral overlapping. The measured full width at half maximum (FWHM) for the aforementioned wideband luminescence was about 203 nm with Nd2O3 and Tm2O3 concentrations of 0.015 mol. % and 0.5 mol. %, respectively, and exhibited a further ∼60% increase in peak intensity after the incorporation of 0.4 mol. % amount of CeO2, which arises from the phenomena of cross relaxation and energy transfer among the three trivalent rare earth ions. The experimental evidence presented in this work shows that tellurite glass containing Nd3+, Tm3+, and Ce3+ has potential as an active material for S-, E-, and O-band wideband luminescence.

Using salted egg white in steamed bread: Impact on functional and structural characteristics

Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose–lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality.

Optimizing thermoelectric performance of BiSbPbTe thin films through controlled post-annealing: A comprehensive structural and electronic study

This study investigates the structural and electronic properties of BiSbPbTe thin films, focusing on the impact of post-annealing time and temperature. The X-ray diffraction (XRD) analysis reveals a stable rhombohedral phase formation in all samples, with no secondary phases detected within the detection limit. The high crystallinity of the films is confirmed, and post-annealing leads to an increase in peak intensity, indicating enhanced crystalline structure. Surface morphology analysis using scanning electron microscopy (SEM) demonstrates a transition from inhomogeneous features in as-grown films to homogeneous and dense formations in post-annealed films. The grain size increases with post-annealing time, attributed to diffusion, energy minimization, nucleation, growth, and thermal activation processes. The electronic transport properties, including carrier concentration and conductivity, are influenced by post-annealing temperature and duration. A stable carrier concentration is observed for films post-annealed for up to 2 h, while longer durations decrease due to reduced defect vacancies and grain boundaries. The increase in charge carrier mobility, confirmed by SEM results, contributes to enhanced electrical conductivity. The Seebeck coefficient shows an initial enhancement up to 2 h post-annealing, attributed to defect creation and increased grain boundaries. However, further increases in post-annealing duration result in a decrease in the Seebeck coefficient due to enhanced charge carrier mobility and reduced grain boundaries. The thermoelectric power factor (4.4 μW/cm1K2), determined by the square of the Seebeck coefficient and electrical conductivity, reaches its maximum value in the 2-h post-annealed sample, emphasizing the importance of optimizing post-annealing conditions for improved thermoelectric performance.

Spin and charge interactions between nanographene host and ferrocene.

Ferrocene (FeCp2) was introduced as a non-magnetic guest molecule to activated carbon fibers (ACFs) as a nanographene-based host having localized spins originating from zigzag edges of graphene. The introduction of the guest molecule was confirmed by FTIR for ACFs-FeCp2 introduced at 55 (150) °C (FeCp2-ACFs-55(150)). The appearance of satellite Fe2p peaks and the increase in shake-up peak intensity of the C1s in the XPS spectrum proved the emergence of charge-transfer host-guest interaction in FeCp2-ACFs-150, supported by the red-shift of the G-band in the Raman spectrum. The six-times enhancement in the spin concentration in FeCp2-ACFs-150 compared with ACFs indicates the spin magnetism of the non-magnetic guest FeCp2+ molecule induced by a charge-transfer host-guest interaction in the nanographene host. The larger ESR linewidth than that expected from the dipolar interaction estimated by the localized spin concentration suggests the exchange interaction between the nanographene and FeCp2 spins. The narrowing of the ESR linewidth of FeCp2-ACFs-55 upon higher excitation microwave power suggests the inhomogeneity of the environment for FeCp2+ molecules in the nanographene host. The observed induction of spin magnetism by the interfacial interactions between the nanographene host and the guest molecules will be a promising strategy for developing a new class of molecular magnets.

Effect of stearic acid modification on properties of pearl millet starch

AbstractThe present study aims Pennisetum glaucum (commonly known as pearl millet) starch modification with stearic acid at various concentrations (2.4, 2.6, and 4.8%) to improve starch functionality. The interaction of stearic acid and starch was verified by X-ray diffractogram which showed peaks at 15.1°, 23.2°, and a doublet with peaks at 17.1° and 18°confirming that an A-type crystalline starch was successfully isolated from pearl millet. The crystallinity pattern of the starch-stearic acid complex was similar to native starch, but there was a slight increase in peak intensity, and an additional peak at 21.42° (SSA3) was recorded, which might be due to aggregates of stearic acid. The surface of the starch granules was slightly dented and punctured as a result of the stearic acid modification, which SEM confirmed. DSC pattern showed that compared to native starch, the starch-stearic acid complex had higher peak temperatures of 123.21 °C (SSA3), demonstrating greater thermal stability. Complex formation was also interpreted from the FTIR spectrum, which showed a small peak at 1698 cm−1 in starch-stearic acid composite samples, which might be due to the stretching vibration of C═O of stearic acid. The complexing index of the sample increased from 26.81 to 90.32% on increasing the stearic acid concentration from 2.4 to 4.8%, respectively. This characterization confirmed the reaction between the hydroxyl group of starch and stearic acid, which showed an increase in thermal stability and can also help improve hydrophobicity, which implies that this complex has the potential for usage in food packaging with improved barrier properties. Graphical abstract

Aberration correction by polynomial approximation for synthetic aperture ultrasound imaging

AbstractBackgroundPreviously, there has been some work in the field of optical imaging on phase compensation by employing Legendre polynomials as an expansion of the phase function, and this seems to be an appealing unstudied area in the field of ultrasound imaging.PurposeThe paper is devoted to solving one of the problems of enhancing the authenticity of diagnostics data obtained in ultrasound visualization systems and presents a novel approach to aberration correction, which ensures a reliable eliminating of phase distortions. The novelty of the proposed approach consists in the use of the decomposition of the wave front by Legendre polynomials to approximate aberrations of the phase front of ultrasonic waves propagating through distorting layers.MethodsThe phase aberrations are corrected using a single sector probe that captures echoes in synthetic aperture mode. The proposed method approximates the changes in the wave front by means of the Legendre polynomials. The performance was investigated by placing a 13‐mm‐wide ultrasonic probe with 64 elements operating at 2 MHz on the surface of a commercial quality control phantom ATS Model 539 through a distorting layer. The following metrics were measured: peak value, root mean square (RMS), full width at half maximum (FWHM), contrast‐to‐noise ratio (CNR). During the experiments, three different aberrators were used interchangeably as distorting layers, two of which were made of photopolymer resin with RMS values of 39 and 97 ns and a speed of sound close to that of a human temporal bone tissue, and the third was an ex vivo human temporal bone with the RMS value of 44 ns. To test the correction, three regions inside the phantom were examined. Two‐sided nonparametric Wilcoxon rank‐sum test was used for assessing the statistical significance. The significance level for this study was set at α ≤ 0.05. To counteract the problem of multiple comparisons, the p‐values were adjusted by the Holm–Bonferroni correction method.ResultsThe statistically significant results have demonstrated the possibility of increasing peak intensity value up to 3.08 times, reducing the RMS width and FWHM of the intensity angular distribution down to 60% and 82%, respectively, and increasing CNR up to 2.12 times by using the proposed phase distortion correction method, compared with the case without correction. The results show that the method can be used as an effective aberration correction technique for all tested regions inside the phantom and distorting layers. Its usage allowed correcting up to 97% of the aberrations caused by the ex vivo temporal bone model.ConclusionThe results show that the usage of the proposed method for aberration correction can successfully increase the intensity and reduce the angular width of the ultrasound wave scattered by the point targets inside the phantoms. The method works with different distorting layers and is capable of correcting phase aberrations in multiple sections of the sonogram. The limitation of the proposed method consists in the fact that it requires the use of aperture synthesis and access to raw radiofrequency data, which restricts its application in common scanners.