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Conversion electron Mössbauer Spectroscopy (CEMS) studies have been conducted on Fe implanted amorphous and crystalline SiO2 which were annealed in air up to a temperature of 1000oC. For both samples, dramatic changes set in after the 1000oC anneal and the CEM spectra are dominated by strong ferromagnetic sextets. In the amorphous sample, the sextet is characterized by magnetic hyperfine fields of 33T, 31T and 29 T, consistent with the formation α-Fe nanoclusters. In the crystalline sample the ferromagnetic sextet has spectral parameters of δ = 0.38(3) mm/s and Bhf = 52.3T, consistent with formation of α-Fe2O3 clusters, reflecting the precipitation of the implanted Fe into such clusters. The line ratios of lines 1, 2 and 3 (and 6, 5 and 4) of the sextet are 3:4:1, reflecting alignment of the magnetic moment of the precipitates normal to the c-axis of the sample surface. [ABSTRACT FROM AUTHOR]

In this study, we have reported the synthesis of both pure and bismuth‐doped lead oxide nanoparticles using solvothermal method. The synthesized nanomaterials were analyzed to assess their structure, crystallinity, phase, maximum absorption and band gap. The electrical characteristics of the fabricated nanostructures were evaluated using cyclic voltammetry (CV) and electron impedance spectroscopy (EIS). The maximum specific capacitance and energy density, 349.96 F/g and 95.27 Wh/g respectively, were attained at a scan rate of 200 mV/s in pure lead oxide. The synthesized pure lead oxide has displayed remarkable cyclic stability, retaining approximately 83 % of its performance even after undergoing 2000 cycles. The addition of bismuth to the lead oxide appeared to inhibit the electrochemical properties of lead oxide due to bismuth ion adsorption. This effect is directly concerned with the amount of dopant which predicted the increase in bismuth contents potentially suppressed the performance of the lead oxide. Our study provides insights into the possible uses of lead oxides in energy storage and conversion devices by revealing a previously unexplored method for optimizing their electrochemical characteristics. The understanding of oxide‐based materials in materials science and electrochemistry is expected to advance with the use of this novel technology. [ABSTRACT FROM AUTHOR]

Juglone, a quinonic compound present in walnut extracts, was proposed as a restoring agent for hair keratin treated with permanent or discoloration processes. The proposed mechanism of restoration by juglone involves the formation of a Michael adduct between the quinone and the thiol moieties of cysteine residues. To this purpose, the first part of the present paper involved the spectroscopic study of the product of the reaction between juglone and N-acetyl-L-cysteine as a model compound. IR spectroscopy and Scanning Electron Microscopy (SEM) monitored the chemical and morphological variations induced by applying juglone to hair keratin. In order to simulate the most common hair treatments (i.e., permanent and discoloration), juglone was applied to hair that had been previously treated with a reducing agent, i.e., methyl thioglycolate (MT) or with bleaching agents (based on hydrogen peroxide and persulfates) followed by sodium hydrogen sulfite. IR spectroscopy allowed us to monitor the formation of Michael adducts between juglone and cysteine residues: the Michael adducts' content was related to the cysteine content of the samples. In fact, MT and sodium hydrogen sulfite favored the reduction of the disulfide bonds and increased the content of free cysteine residues, which can react with juglone. SEM analyses confirmed the trend observed by IR spectroscopy since hair samples treated with juglone adopted a more regular hair surface and more imbricated scales, thus supporting the possible use of juglone as a restoring agent for damaged hair keratins. [ABSTRACT FROM AUTHOR]

[Display omitted] • An operando crystal-amorphous transformation of VOOH is demonstrated via in-situ / ex-situ structural analyses. • The unique crystal-amorphous transformation allows the obtained amorphous V 2 O 5 to achieve the high capacity, superior rate performance, and high energy and power densities. • The potentiality of cathode materials via operando crystal-amorphous transformation to achieve the enhanced zinc storage is confirmed. Aqueous zinc-ion batteries have obtained broad attention due to their high safety, eco-friendliness, and low cost. However, they are still in the developing stage considering the limited candidate of high-performance cathode materials. Furthermore, the intrinsic storage zinc mechanism is also needed to uncover. Here, we propose an operando crystal-amorphous transformation of tunnel-type VOOH and the obtained amorphous V 2 O 5 serves as a high-performance zinc-ion battery cathode. In-situ X-ray diffraction corroborates the unique operando crystal-amorphous transformation of VOOH during the initial charging process. X-ray photoelectron spectroscopy and transmission electron microscopy further demonstrate the element valence evolution and the lattice structure change, respectively. The operando electrochemical crystal-amorphous transformation allows the obtained amorphous V 2 O 5 to achieve the high capacity of ∼ 350.7 mAh g−1, rate performance (151.2 mAh g−1 at 6.4 A g−1), energy and power densities (137 Wh kg−1 at 6831 W kg−1), unveiling a promising approach of cathode materials via operando crystal-amorphous transformation to achieve the enhanced zinc storage. [ABSTRACT FROM AUTHOR]

The short de Broglie wavelength and strong interaction empower free electrons to probe structures and excitations in materials and biomolecules. Recently, electron-photon interactions have enabled new optical manipulation schemes for electron beams. In this work, we demonstrate the interaction of electrons with nonlinear optical states inside a photonic chip–based microresonator. Optical parametric processes give rise to spatiotemporal pattern formation corresponding to coherent or incoherent optical frequency combs. We couple such “microcombs” to electron beams, demonstrate their fingerprints in the electron spectra, and achieve ultrafast temporal gating of the electron beam. Our work demonstrates the ability to access solitons inside an electron microscope and extends the use of microcombs to spatiotemporal control of electrons for imaging and spectroscopy. [ABSTRACT FROM AUTHOR]

We investigate the ionisation and fragmentation dynamics of free camphor molecules and camphor-doped helium nanodroplets by extreme ultraviolet (EUV) and soft x-ray photons using velocity map imaging combined with photoelectron-photoion coincidence (VMI-PEPICO) spectroscopy. We notably find that the Penning ionisation of camphor in He nanodroplets at h ν = 21.43 eV is soft with nearly identical Penning ionised electron spectra correlated to different molecular fragments. Further, fragmentation following ionisation at all photon energies exhibit a droplet-specific mass peak equivalent to the missing mass of CO, suggesting suppression of further fragmentation inside the droplet. This work reveals unusual features of photoionisation of organic molecules doped in He nanodroplet motivating further experimental and theoretical explorations. [ABSTRACT FROM AUTHOR]

Chitosan is a marine polysaccharide commonly seen in the crustacean family, and the exoskeleton is covered by chitosan. In this study, shells of mud crabs were subjected to chitosan extraction which has been followed by demineralization, deproteination, and deacetylation. The chemical compositions of chitosans were characterized using Fourier transform infrared spectroscopy (FTIR). It exhibits antimicrobial activity against pathogens - E.coli, Staphylococcus, Klebsiella pneumonia, Bacillus cereus, and Salmonella typhi. It has therefore received attention as a potential food preservative. Transform Infrared Spectroscopy (FTIR) also spots out chemical bonds in a molecule by creating rather an infrared absorption spectrum. FTIR is an effective instrument for analysis and for also detecting the functional groups as well as characterizing covalent bonding information. FTIR spectroscopy finds out the functional molecules involved in the synthesis of nanoparticles and also, provides accuracy and reproducibility, which helps to detect small absorbance changes in the sample. The chemical compositions of chitosans were characterized further using FESEM.The FESEM pattern performs or indicates the silver nanoparticles to be embedded in a matrix of CS. The size of the particles is seen as with their uniformity. Not only this, but also the FESEM image of Ag nanoparticles shows somewhat the particles of spherical shape. Also, by Transmission Electron Microscopy (TEM) technique, the chemical compositions of chitosans were characterized. It exhibits that synthesized chitosan/silver nanocomposites have indeed a shape such as spherical with their uniformity as to their dispersion. Further, the chemical compositions of chitosans were characterized using Electron dispersive spectroscopy (EDS). The EDS histograms reveal rather successfully the percentage weight ratios of the elements found on the chitosan surface and the nanosilver concentrations in this study. In addition, by XRD analysis the chemical compositions of chitosans were characterized. It recognizes the multifarious crystalline phases present in the material so that the information touching the chemical compositions are revealed. In this study, mcf-7 cell line is chosen. Mcf-7 is a commonly used breast cancer cell line. For evaluation of anticancer study against mcf-7, the mcf-7 cell line is chosen for the study. In this study, anti-cancer study was very specially subjected to research and the chemical compositions of chitosans were characterized very seriously by FESEM, TEM, EDS, FTIR, and XRD for such anticancer study and therapy. [ABSTRACT FROM AUTHOR]

A second-generation hyperbranched polyester with the terminal carbamoyl phosphonate groups has been synthesized. The structure of the resulting polyester has been studied by IR, 1H NMR, 31P NMR, and electron spectroscopy. It has been found that 25% of the terminal OH groups of polyester polyol were subjected to functionalization. Using the TGA method, the thermal stability temperature of the resulting polyester was evaluated to be 138°C. We have synthesized a complex of the resulting polyester with the Pd(II) ions, and the complex structure has been studied by IR and electron spectroscopy. The composition of the ligand–Pd(II) complex has been evaluated to be 1 : 6. We have found by the TGA method that this complex is thermally stable up to 207°C. The temperature of reduction of the Pd(II) ions by molecular hydrogen to Pd(0) has been assessed as –20.6°C. Electron microscopy has been used to demonstrate the spherical morphology of hyperbranched polyester polycarbamoyl phosphonate with Pd(0) atoms, with the predominant fraction being 1.5 μm. It has been shown that the use of hyperbranched polyester polycarbamoyl phosphonate as a catalyst provides the activation energy of 55.8 kJ/mol for hydrogenation of α-methylstyrene to cumene with the effective rate constant of 1.950×10–2 L/(gcat s) at 45°C and atmospheric pressure. The results indicate the prospects of using hyperbranched polyester polycarbamoyl phosphonate as a matrix to obtain catalysts for the hydrogenation of unsaturated compounds. [ABSTRACT FROM AUTHOR]

Different electrochemical techniques, such as electrochemical "impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), and potentiodynamic polarization (PDP), and mass reduction at various temeratures were used to evaluate the inhibitory potential of Terfeziaceae extract as a corrosion inhibitor for Cu in HNO3 corrosive arrangements. The adsorption was analyzed utilizing Temkin adsorption isotherm, and the adsorption factors were considered. The detections illustrated that the Terfeziaceae extract shown maximum inhibition capacity (% IE) reached to 98.1% at concentration of 300 ppm, 25°C. "x‐ray electron spectroscopy (XPS), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) surface study techniques have all supported the existence of a protective layer on the Cu surface. This extract operates as a mixed‐type inhibitor, according to PDP data." The current research presents highly significant findings in the preparation and design of original, environmentally friendly, sustainable inhibitors with high inhibitory power. [ABSTRACT FROM AUTHOR]

Reticulated porous MgO ceramics were fabricated by suspension impregnation method, which involves replication of polyurethane foam with mixed slurry of MgO and MgF2 and subsequent sintering treatments. The objective of the present study is to find a suitable method to ensure uniform macropore or micropore structure of ceramics foam using low-melting additives at moderate sintering temperatures. The microstructures of Magnesia Foam Ceramics (MFC) were evaluated by scanning electron microscopy (SEM) coupled with X-ray diffraction (XRD). The loading amount and apparent porosity of MFC are related to the slurry viscosity and PPI of PU foam. More importantly, compared with different filtration methods of molten crude magnesium, we can draw a conclusion that MFC can clean MgO inclusions and refining agent effectively based on the test results of electron dispersive spectroscopy (EDS) and density of crude magnesium before and after filtration.These results are attributed to the formation of filter sieve removing particles larger than or close to the pore size and to liquid inclusions held to the filter wall by surface forces, owing to specific surface area resulted by macropores and micropores formed in MFC in the presence of polyurethane foam and sintering binder MgF2 powders. [ABSTRACT FROM AUTHOR]

This study investigated the thermoluminescence properties of undoped CaF2 nanoparticles synthesized via co-precipitation with ethanol. X-ray diffraction revealed pure CaF2 nanoparticles with a complete cubic structure and an average crystallite size of 36.5 nm. Scanning electron microscopy confirmed the nanoscale size, averaging 51.23 nm. Electron dispersive spectroscopy analysis showed that the sample mainly consists of Ca and F, with oxygen potentially introducing defects in the crystal structure. Synthesized nanoparticles TL glow curves exposed to 7 mGy of 90Sr beta rays exhibited a prominent peak at 205 oC in thermoluminescence glow curves, likely due to oxygen-induced defects that act as thermoluminescence activators. The thermoluminescence activating energy and the frequency factor of the CaF2 nanoparticles were determined using initial rise methods of approximately 0.83 eV and 5.99 x 10-19, respectively. [ABSTRACT FROM AUTHOR]

Flexible crystal structures, which exhibit single-crystal-to-single-crystal (SCSC) transformations, are attracting attention in many applied aspects: magnetic switches, catalysis, ferroelectrics and sorption. Acid treatment for titanosilicate material AM-4 and natural compounds with the same structures led to SCSC transformation by loss Na+, Li+ and Zn2+ cations with large structural changes (20% of the unit-cell volume). The conservation of crystallinity through complex transformation is possible due to the formation of a strong hydrogen bonding system. The mechanism of transformation has been characterized using single-crystal X-ray diffraction analysis, powder diffraction, Rietvield refinement, Raman spectroscopy and electron microscopy. The low migration energy of cations in the considered materials is confirmed using bond-valence and density functional theory calculations, and the ion conductivity of the AM-4 family's materials has been experimentally verified. [ABSTRACT FROM AUTHOR]

Gas-phase anions present an ideal playground for the exploration of excited-state dynamics. They offer control in terms of the mass, extent of solvation, internal temperature, and conformation. The application of a range of ion sources has opened the field to a vast array of anionic systems whose dynamics are important in areas ranging from biology to star formation. Here, we review recent experimental developments in the field of anion photodynamics, demonstrating the detailed insight into photodynamical and electron-capture processes that can be uncovered. We consider the electronic and nuclear ultrafast dynamics of electronically bound excited states along entire reaction coordinates; electronically unbound states showing that photochemical concepts, such as chromophores and Kasha's rule, are transferable to electron-driven chemistry; and nonvalence states that straddle the interface between bound and unbound states. Finally, we consider likely developments that are sure to keep the field of anion dynamics buoyant and impactful. [ABSTRACT FROM AUTHOR]

Spontaneous avalanche to plasma begins in the core of an ellipsoidal Rydberg gas of nitric oxide. Ambipolar expansion of NO $^+$ draws energy from avalanche-heated electrons. Then, cycles of long-range resonant electron transfer from Rydberg molecules to ions equalize their relative velocities. This sequence of steps gives rise to a remarkable mechanics of self-assembly, in which the kinetic energy of initially formed hot electrons and ions drives an observed separation of plasma volumes. These dynamics adiabatically sequester energy in a reservoir of mass transport, starting a process that anneals separating volumes to form an apparent glass of strongly coupled ions and electrons. Short-time electron spectroscopy provides experimental evidence for complete ionization. The long lifetime of this system, particularly its stability with respect to recombination and neutral dissociation, suggests that this transformation affords a robust state of arrested relaxation, far from thermal equilibrium. We see this most directly in the excitation spectrum of transitions to states in the initially selected Rydberg series, detected as the long-lived signal that survives a flight time of $500\ \mathrm {\mu }$ s to reach an imaging detector. The initial density of electrons produced by prompt Penning ionization, which varies with the selected initial principal quantum number and density of the Rydberg gas, determines a balance between the rising density of ions and the falling density of Rydberg molecules. This Penning-regulated ion-Rydberg molecule balance appears necessary as a critical factor in achieving the long ultracold plasma lifetime to produce spectral features detected after very long delays. [ABSTRACT FROM AUTHOR]

A discrepancy in the determination of the proton's charge radius, r p , between muonic hydrogen spectroscopy versus classic atomic spectroscopy and electron scattering data has become known as the proton radius puzzle. Extractions of r p from electron scattering data require determination of the slope of the proton's charge form factor, G E p , in the limit of Q 2 → 0 through fitting and extrapolation. Some works have presented the Z-transformation fitting technique as the best choice for this type of extraction due to the true functional form of G E p being mathematically guaranteed to exist within the parameter-space of the fit function. In this work, we test this claim by examining the mathematical bias and variances introduced by this technique as compared to the more traditional Q 2 fits using statistically sampled G E p parameterizations with known input radii. Our tests conclude that the quality of the Z-transformation technique depends on the range of data used. In the case of new experiments, the fit function and technique should be selected in advance by generating realistic pseudodata and assessing the power of different techniques. [ABSTRACT FROM AUTHOR]

The pigments consumed in grazing give the milk from dual-purpose cows raised in tropical conditions a yellowish color, affecting the quality and price of the milk. This study aimed to develop an economical method with supplementary pectin to antagonize the availability of carotenes by designing microparticles with shellac and palm oil as a viable alternative to protect pectin degradation against rumen microbes. Three preparations of microparticles based on citrus pectin were synthesized: unprotected (PnP), protected with palm oil (PwP), and protected with palm oil and shellac (PwPL) microparticles. Samples were roughly characterized by spectroscopy and electron microscopy techniques. The effect of PnP, PwP, and PwPL on blood metabolites and physicochemical characteristics of the milk of grazing lactating cows was evaluated through in vivo assays. The release of citrus pectin from microparticles was determined as uronic acids using solutions with distinct pH, whereas its degradation was studied using in situ tests. Results revealed that PnP, PwP, and PwPL are amorphous structures with sizes that range from 60 to 265 nm or 750 to 3570 µm and have surface charges that range from −11.5 to −50.2 mV. Samples exhibited characteristic peaks during FTIR analyses that corresponded to O-H, C=O, and COOCH3 groups and bands within the UV-vis region that indicated the absorption of pectin. The EDS analysis revealed the presence of carbon, oxygen, or calcium in samples. The release of uronic acids was higher at pH 2–3 with PwPL. The in situ degradability of PnP, PwP, and PwPL was 99, 28.4, and 17.7%, respectively. Moreover, PwPL decreased the blood concentration of glucose, cholesterol, and lactate. In contrast, 100 g of pectin per animal daily during the feed process reduced yellow coloring. In conclusion, designing particles protected with lipids and polymers as shellac is an economical method that resists degradation at pH levels greater than five. [ABSTRACT FROM AUTHOR]

Two historic‐period metal artifacts were provided by the New Mexico Historic Sites to Los Alamos National Laboratory for non‐destructive analysis. The artifacts were a crossbow quarrel (or bolthead) and a reliquary pendant recovered from Kuaua Pueblo (also known as the Coronado Historic Site) in Bernalillo, NM. The quarrel is a heavily patinated metal that had been flattened due to compressive forces. The pendant consisted of a metal casing that had previously surrounded two center gemstones on the front and rear face of the pendant. The gemstone in the rear setting had fractured and was displaced from the setting, leaving only a small, loose fragment within the pendant for study. The front gem appeared to be very dark, near‐black in color, and the fragment of the rear gem was a bright red color. The artifacts were analyzed to ascertain their composition and glean insight into their provenance using the following X‐ray techniques: X‐ray computed tomography, confocal micro X‐ray fluorescence, and X‐ray diffraction. Infrared spectroscopy and electron microscopy were used on selected areas. Ultraviolet Raman spectra were collected on the two gems and the pendant. The metal material of the artifacts was found to be primarily composed of copper. The gems in the pendant were composed of manganese (front gem) and calcium (side gem). [ABSTRACT FROM AUTHOR]

Purpose: This study aims to using Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscope/energy dispersive Xray spectrometer to identify different automotive coatings for forensic purpose. Design/methodology/approach: Two four-layered samples in a hit-and-run case were compared layer by layer with three different methods. FTIR spectroscopy was used to primarily identify the organic and inorganic compositions. Raman spectrum and scanning electron microscope/energy dispersive Xray spectrometer (SEM-EDS) were further used to complement the FTIR results. Findings: Two weak and tiny peaks in one layer found between two samples by FTIR, Raman microscope and SEM-EDS verified the result of differences. The study used the three instruments in combination and found it's effective in sensing coatings, especially in the inorganic additives. Research limitations/implications: Using these three instruments in combination is more accurate than individually in multilayered coating analysis for forensic purpose. Practical implications: The three different instruments all present unique information on the composition, and provided similar and mutually verifiable results on the two samples. Originality/value: With this method, scientists could identify and discriminate important coating evidences with tiny but characteristic differences. [ABSTRACT FROM AUTHOR]

There is a widespread interest in time-resolved electron spectroscopies such as ultrafast electron diffraction, ultrafast electron microscopy, and ultrafast electron energy loss spectroscopy. These techniques require pulsed electron beams with both high current and brightness. LaB6 is commonly used as a thermionic emitter because of its low work function and high electron yield. However, its use as a pulsed photocathode has not been widely explored. Here, we present measurements of the electron yield from a LaB6 filament exposed to 392 nm UV ultrafast laser pulses under a wide range of filament temperatures. We find that sample heating strongly enhances photoelectron yield, an effect known as thermionically enhanced photoemission. However, it also creates potentially undesirable, continuous thermionic background. We conclude that the ideal optimal operating conditions strongly depend on the type of measurement and require defining and quantifying an appropriate figure of merit. [ABSTRACT FROM AUTHOR]

Biobased adsorbents have been developed for the removal of dye contaminants in aqueous solution. Hydrogel beads from alginate containing TEMPO-oxidized cellulose nanofibers (TOCNF) grafted with polyethyleneimine (PEI), namely Al/TOCNF-PEI, were prepared and evaluated as a new adsorbent for Congo Red (CR). The Al/TOCNF-PEI hydrogel beads were made with various concentrations of TOCNF/PEI, the optimum concentration is 45 wt% or Al/TOCNF-PEI45. The hydrogel was characterized by using Fourier-Transform Infrared spectroscopy and Scanning Electron Microscopy. The adsorption performance of the Al/TOCNF-PEI hydrogel beads towards CR was investigated in terms of changing of TOCNF-PEI content, initial concentration, pH, contact time, and adsorbent dosage. The maximum capacity of the adsorbent for CR was found to be 9.437 mg/g at the optimal conditions (pH = 3; T = RT) with the removal efficiency reaching 95 %. This result was ascribed to occur due to the electrostatic attraction between the protonated hydroxyl group and ammonium moiety of the hydrogel beads and the anionic sulfonate group of the CR. Upon fitting the adsorption data, the adsorption mechanism was consistent with the Freundlich isotherm and pseudo-second-order kinetic models. Based on this finding, the low-cost Al/TOCNF-PEI45 hydrogel beads demonstrated a great potential for the removal of hazardous dyes in wastewater. [ABSTRACT FROM AUTHOR]

The results of complex experimental studies of the parameters of thin coatings of SiO2 oxides on Si, formed by thermal oxidation at temperatures of 1200 °C, including studies using electron and X-ray spectroscopy, IR-Fourier spectrometer IRTracer-100 - developed by Shimadzu, Raman scattering, and test electrophysical structures, are presented. Data have been obtained that for a silicon dioxide thickness of about 400 nm, the porosity of the coating does not exceed 2/cm2, and the electric field strength for the breakdown of the dioxide reaches 5·106 V/cm. The crystal structure of SiO2 is triclinic, lattice period a = 4.9160 Å, b = 4.9170 Å, c = 5.4070 Å, a = 90.000, b = 90.000, γ = 120.000, density 2.64 g/cm³. [ABSTRACT FROM AUTHOR]

High-harmonic spectroscopy is an all-optical technique with inherent attosecond temporal resolution that has been successfully employed to reconstruct charge migration, electron-tunneling dynamics, and conical-intersection dynamics. Here, we demonstrate the extension of two key components of high-harmonic spectroscopy, i.e., impulsive alignment and measurements with multiple driving wavelengths to 1,3-cyclohexadiene and benzene. In the case of 1,3-cyclohexadiene, we find that the temporal sequence of maximal and minimal emitted high-harmonic intensities as a function of the delay between the alignment and probe pulses inverts between 25 and 30 eV and again between 35 and 40 eV when an 800-nm driver is used, but no inversions are observed with a 1420-nm driver. This observation is explained by the wavelength-dependent interference of emission from multiple molecular orbitals (HOMO to HOMO-3), as demonstrated by calculations based on the weak-field asymptotic theory and accurate photorecombination matrix elements. These results indicate that attosecond charge migration takes place in the 1,3-cyclohexadiene cation and can potentially be reconstructed with the help of additional measurements. Our experiments also demonstrate a pathway toward studying photochemical reactions in the molecular frame of 1,3-cyclohexadiene. [ABSTRACT FROM AUTHOR]

Samples suitable for electron diffraction studies must satisfy certain characteristics such as having a thickness in the range of 10–100 nm. We report, to our knowledge, the first successful synthesis technique of nanometer-thin sheets of single-crystalline thymine suitable for electron diffraction and spectroscopy studies. This development provides a well-defined system to explore issues related to UV photochemistry of DNA and high intrinsic stability essential to maintaining integrity of genetic information. The crystals are grown using the evaporation technique, and the nanometer-thin sheets are obtained via microtoming. The sample is characterized via x-ray diffraction and is subsequently studied using electron diffraction via a transmission electron microscope. Thymine is found to be more radiation resistant than similar molecular moieties (e.g., carbamazepine) by a factor of 5. This raises interesting questions about the role of the fast relaxation processes of electron scattering-induced excited states, extending the concept of radiation hardening beyond photoexcited states. The high stability of thymine in particular opens the door for further studies of these ultrafast relaxation processes giving rise to the high stability of DNA to UV radiation. [ABSTRACT FROM AUTHOR]

Brake pads are crucial for vehicle safety, converting kinetic energy to halt motion. They come in types like organic, semi -metallic, ceramic, and metallic. Beyond automotive, brake pads find application in industries such as aerospace, railways, manufacturing, and wind energy for controlled deceleration and safety. This study is primarily concerned with the quality and appropriateness of ceramic brake pads for automotive applications, which are an essential aspect of braking systems for vehicles. The performance characteristics of ceramic brake pads are well established, and this study explores the variables affecting their quality. Under high pressure, brake pad samples are prepared in the study using Powder Metallurgy (PM), which guarantees superior mechanical qualities by removing interface bonding problems. The samples are then sintered at 2850. Hardness, temperature resistance, wear resistance, and Electron Dispersive Spectroscopy (EDS) analysis are all included in the evaluation to ascertain the make-up and distribution of the materials in the brake pad. EDS sheds light on the degree of sintering and the presence of reinforcements. Heat resistance is evaluated using controlled thermal testing, while wear resistance and hardness are determined through Rockwell hardness testing and wear tests, respectively. These measurements are validated for use in automotive disc braking systems for vehicles and motorcycles. The findings are more reliable thanks to statistical analysis done with MINITAB. The study highlights research gaps in environmentally friendly materials, emerging technology impacts, and long-term brake pad durability. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy is a major and valuable chemical analysis technique that can bring a wide range of information if one takes time to carefully interpret the spectra. In particular, many metrological developments deal with the modeling of photoelectron peaks while X-Auger transitions still remain hardly exploited. Here, an innovative approach examining these spectral features in a complementary way is presented and illustrated on a concrete case dealing with chemical changes of indium in the InSb semiconductor during its air aging. Indium contains an extensive range of photopeaks along the energy scale, meaning electrons emitted from different escape depths are present on the same widescan spectrum, and, thus, information from different depths is accessible. Specifically, this study focuses on indium's X-Auger electron spectroscopy (X-AES) transitions and decomposition to track the outer surface chemistry evolution of the InSb semiconductor. To this end, we compared linear and nonlinear least-squares approaches to decompose In M4,5N4,5N4,5 X-AES transition and demonstrate oxide growth progression. For both approaches, we applied the vectorial method (also known as the informed amorphous sample model) to retrieve the different chemical environments present during air aging. Linear and nonlinear least-squares approaches were both found to yield comparable results, with a comparative error of less than 10%. Over time, a progressive growth of the oxide layer was demonstrated, ranging from 0.3 ± 0.2 to 2.9 ± 0.2 nm using the X-AES transitions. Additionally, decomposition of the In 3d and In 4d photoelectron peaks showed a lower thickness of oxide with time due to the lesser surface sensitivity of these peaks. [ABSTRACT FROM AUTHOR]

Waste fly ash (WFA) and secondary aluminum dross (SAD) are common solid wastes inducing environmental pollution. These materials contain certain active substances that can be used in cement-based materials. Therefore, cement concrete can be used to solidify these solid wastes. In this study, the influence of the assembly unit of secondary aluminum dross (SAD) and waste fly ash (WFA) on the properties of ultra-high-performance concrete (UHPC) is investigated. The slump flow, the plastic viscosity, the yield shear stress, and the initial setting time of fresh UHPC are measured. Moreover, the flexural and compressive strengths and the dry shrinkage rate (DSR) are determined. The electrical resistance and reactance are tested. The electron microscopy spectroscopy (EDS), thermogravimetric analysis (TG), and X-ray diffraction spectrum (XRD) curves are obtained for revealing the mechanism of macroscopic performances. Results show that due to the optimal specific surface area and the volcanic ash effect, the UHPC with the assembly unit of 50% SAD and 50% WFA provides the highest slump flow, DSR, and mechanical strengths, while the corresponding plastic viscosity, yield shear stress, and electrical resistance are the lowest. The SAD can delay the setting time of UHPC. The relationship between the electrical resistance or the electrical reactance and the mass ratio of SAD accords with the quadratic function. The corresponding electrical resistance is the lowest. The relationship between the mechanical strengths and the electrical resistance fits with the cubic function. The leaching amounts of Zn and Cr increase in the form of cubic function with the immersing time. Meanwhile, the SAD can decrease the Zn and Cr by 0%–46.3% and 0%–45.2% respectively. As obtained from the EDS results, the element of Al is increased by adding SAD. The XRD curves show that the crystals of Al2O3 are increased and the SiO2 crystals are decreased by the added SAD. UHPC with 50% SAD exhibits the highest compact microstructures and the least Ca(OH)2 and 3CaO·SiO2 hydration products. The TG results show that UHPC with 50% SAD shows the lowest TG values of all the groups. This research will provide new UHPC materials and techniques applied in solidifying the WFA and SAD in the future. [ABSTRACT FROM AUTHOR]

Graphene oxide/polydopamine-polyacrylamide nanocomposite as sorbent for dispersive micro-solid phase extraction of diazinon from environmental and food samples was synthesised and coupled with high-performance liquid chromatography-ultraviolet detector. The prepared sorbent was characterised by analytical techniques such as Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy–energy-dispersive spectroscopy and thermal gravimetric analysis. Main parameters affecting extraction efficiency of diazinon using dispersive micro-solid phase extraction such as sorbent amount, elution solvent and its volume, sorption and desorption times and pH of sample solution were investigated and optimised. The optimum values are as follow; sorbent amount, 0.2 g; elution solvent, methanol; elution solvent volume, 2.5 mL; sorption time, 10 min; desorption time, 4 min and pH of sample solution, 3. Under the optimised conditions, method detection limit and limit of quantitation values were 0.24 and 1.0 ng/mL, respectively. Relative recovery data for several real samples were obtained within the range of 82.0–98.0% with a relative standard deviation less than 6.5%. The proposed method was successfully applied to quantitative determination of diazinon in several environmental and food samples. [ABSTRACT FROM AUTHOR]

In order to solve the problem of frequent snow and ice removal in winter, a micro-surfacing pavement with active snow and ice removal and slow-release function is developed. The snow-melting agent with sodium acetate, calcium acetate, and potassium acetate as the main components was prepared, and the optimum proportion was determined. With the help of hygroscopicity and oil absorption tests, the optimum surface modifier and its optimum concentration were determined. The microstructure of the snowmelt agent were characterized by infrared spectroscopy and scanning electron microscopy. The influence of snow-melting agent on the road performance was explored. The results show that the optimum proportion of sodium acetate, calcium acetate and potassium acetate is 37, 15 and 48 % respectiveiy. When the surface modifier: hydrogen silicone oil and KH560 solution concentration was 4.0% and 1.0% respectively, the slow-release effect was the optimum. The wear resistance and high temperature stability of micro-surfacing with the snowmelt agent were increased by 2.5 % and 8.2 %, respectively. It is most reasonable to determine that the optimal replacement amount of mineral powder is 50%. It is necessary to study the distribution of self-made snowmelt agent in the mixture in the future. [ABSTRACT FROM AUTHOR]

This study reports on the synthesis and characterization of a series of lithium gallate (LiGa5O8) phosphors doped with varying concentrations of Eu3+ ions. X-ray powder diffraction analysis confirmed the synthesis of the cubic phase of LiGa5O8, with additional peaks corresponding to Eu2O3 at higher dopant concentrations. Rietveld refinement confirmed the formation of a spinel-structured host with a space group of P4322. Ultraviolet-visible spectroscopy was used to analyze the absorption properties of the phosphor material and estimate the bandgap for all synthesized samples, which ranged from 4.75 to 4.95 eV, indicating the formation of a wide bandgap semiconductor stable at room temperature. Morphological and compositional analysis, along with surface mapping, were conducted using field emission scanning electron microscopy, energy dispersive electron spectroscopy, and time-of-flight secondary ion mass spectroscopy. X-ray photoelectron spectroscopy provided insights into the crystal structure and revealed the presence of oxygen vacancies and some other crystal defects. Photoluminescent properties were examined through photoluminescence excitation and emission spectra for all doped samples. Notably, samples doped with 6 and 7 mol% Eu3+ displayed a prominent excitation peak at 247 nm corresponding to the presence of Eu2O3, while the remaining samples exhibited characteristic Eu3+ excitation. Lifetime measurements for both excitation wavelengths showed decay times in the millisecond range. The emission color of all samples resided within the red region of the electromagnetic spectrum, boasting remarkable color purity. The results suggest that this material has potential as a red light-emitting component for LED applications. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanorods and ZnO nanostructures composited with silver (Ag) and multi-walled carbon nanotubes (MWCNTs) have been synthesized by a simple impregnation–calcination method and have been shown to be suitable for use as antimicrobial agents. The preparation method used for composite materials is very simple, time-effective, and can be used for large-scale production. Several analytical techniques, including X-ray diffraction (XRD), scanning electron spectroscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transmission infrared spectroscopy (FTIR), have been used to characterize the prepared ZnO-Ag-MWCNT composite materials. The effects on structural, morphological, and antimicrobial properties of (ZnO)100-x (Ag)x nanocomposites at various weight ratios (x = 0, 5, 10, 30, and 50 wt%) have been investigated. The antimicrobial properties of ZnO composited with Ag nanoparticles and MWCNTs towards both gram-positive and gram-negative bacteria species were studied. The effect of raw MWCNTs and MWCNTs composited with ZnO and Ag on the cell morphology and chemical composition of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was studied by SEM and EDS, respectively. It was found that composite materials made of ZnO-Ag-MWCNTs exhibit greater antibacterial activities toward the microorganisms E. coli and S. aureus than ZnO-Ag, which could be beneficial for efficient antimicrobial agents in water and air treatment applications. [ABSTRACT FROM AUTHOR]

The electronic structure of ultrathin Cs/Bi2Se3 interfaces has been studied by photo electron spectroscopy using synchrotron radiation. The experiments were carried out in situ in ultrahigh vacuum with submonolayer Cs coverages on Bi2Se3 samples. It was found that the adsorption of Cs causes changes in the core level spectra of Bi 4f, Bi 5d, Se 3d. It has been established that Cs atoms are adsorbed predominantly on Bi atoms in the upper surface layer. The states of the valence band were studied for a clean Bi2Se3 surface and for the Cs/Bi2Se3 interface. Near the Fermi level, 2D topological states have been found. Two induced surface states appear in the region of the valence band upon adsorption of Cs. [ABSTRACT FROM AUTHOR]

By methods of electron spectroscopy for chemical analysis and spectroscopy of characteristic losses of electron energy, the electronic structure of barium oxide crystallites doped with other chemical elements, including scandium from scandium-containing phases, was investigated. The physical and physicochemical conditions are formulated, the fulfillment of which allows to form the electronic structure of the scandate cathode with a high level of thermionic emission: the achievement of the minimum ratio of the surface volume concentration of oxygen vacancies and the maximum distance between the top of the valence band and the Fermi level. [ABSTRACT FROM AUTHOR]

Nowadays, ozone contamination becomes dominant in air and thus challenges the research and development of cost-effective catalyst. In this study, metal doped Cu 2 O catalysts are synthesized via reduction of Cu2+ by ascorbic acid in base solutions containing doping metal ions. The results show that compared with pure Cu 2 O, the Mg2+ and Fe2+ dopants enhance the O 3 removal efficiency while Ni2+ depresses the activity. In specific, Mg-Cu 2 O shows high O 3 removal efficiency of 88.4% in harsh environment of 600,000 mL/(g·hr) space velocity and 1500 ppmV O 3 , which is one of the highest in the literature. Photoluminescence and electron paramagnetic spectroscopy characterization shows higher concentration of crystal defects induced by the Mg2+ dopants, favoring the O 3 degradation. The in-situ diffuse reflectance Fourier transform infrared spectroscopy shows the intermediate species in the O 3 degradation process change from O 2 2− dominant of pure Cu 2 O to O 2 − dominant of Mg-Cu 2 O, which would contribute to the high activity. All these results show the promising prospect of the Mg-Cu 2 O for highly efficiency O 3 removal. [Display omitted] [ABSTRACT FROM AUTHOR]

Tungsten carbide-based nano-catalysts (Ni-WC, Co-WC and NiCo-WC) and molybdenum carbide-based nano-catalysts (Ni-MoC, Co-MoC and NiCo-MoC) were synthesised using a carbothermal reduction method. X-ray diffraction, scanning electron microscopy coupled with electron dispersive spectroscopy, x-ray photoelectron spectroscopy and cyclic voltammetry were used to evaluate the prepared electrocatalysts. The cyclic voltammetry results showed that Ni-WC coated electrode displayed the best hydrogen evolution reaction catalytic activity with the lowest overpotential of 1.421 V at a current density of 10 mA cm−2, and a Tafel slope of 135 mV dec−1 which is marginally lower than the benchmark Pt/C coated electrodes. Ni-MoC and Co-MoC coated electrocatalysts also produced current more effectively with a change in potential as compared to the Pt/C coated electrode. The durability test showed Co-WC, NiCo-WC and Ni-MoC coated electrodes to have high stability within a wide range of current densities. [ABSTRACT FROM AUTHOR]

A series of 10 talc (nominally MMg3TSi4O10X(OH)2) and 22 serpentine (nominally MMg3TSi2O5X(OH)4) minerals have been studied by Raman spectroscopy and electron microprobe analysis (EMPA) to establish quantitative relationships between the content of octahedrally coordinated M‐site cations and Raman peak parameters, which would allow for noninvasive material profiling. We show that in the case of talc, the position of the strong and well‐resolved peak near 360 cm−1, related to MO6 vibrations, as well as the integrated intensities of the OH‐stretching Raman signals (3600–3750 cm−1) can be used to determine the amount of MMg and M(Fe2+ + Mn2+) with a precision similar to that of EMPA. In the case of serpentine, the overall shape of the Raman scattering arising from OH‐stretching modes (3600–3750 cm−1) can be initially used to distinguish between the different polymorphs: antigorite, chrysotile, and lizardite, as well as the lizardite‐/chrysotile‐rich polygonal/polyhedral serpentine varieties and then, the full width at half maximum (FWHM) of the strongest MO6 peak at ~380 cm−1 can be used to estimate MMg content in each of the analyzed polymorphs/varieties and a relative error of 5%. In addition, MFe2+ amount in chrysotile and chrysotile‐rich polygonal serpentine can be quantified by FWHM of the peak near 230 cm−1 with a relative error of 5%, whereas MFe2+ amount in antigorite can be derived from FWHM of the peak near 130 cm−1 with similar relative uncertainties. We demonstrate the effectiveness of our approach on two types of rock‐based cultural‐heritage objects, cylinder seals and inscribed gems, where sampling is prohibitive. [ABSTRACT FROM AUTHOR]

Turmeric has been widely studied as a color indicator for pH variations due to its halochromic properties. It has been tested in solution or included in some polymeric matrices. Some studies have demonstrated that its change in color is due to the tautomeric species of curcumin, and this property can be observed even if turmeric is assimilated in a film or nanofiber. Chitosan/polyethylene oxide (PEO) polymers have been tested in previous studies. Polyvinyl alcohol (PVA) nanofibers are used as potential carriers of drugs once they are insolubilized. The aim of this work is to cross-link PVA with citric acid (CA) to insolubilize the nanofibers and determine the effect on turmeric's halochromic properties. The nanofibers were treated with a sodium hydroxide (NaOH) solution, and a chromatic study was undertaken to determine color change. The change in color was assessed by eye (subjective) and by spectroscopy (objective). The nanofibers were characterized, in addition to the colorimetric study, by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) as well. The results demonstrate how thermal treatment induces cross-linking between the nanofibers, allowing them to keep their shape once the NaOH solution is applied to them. The opposite effect (solubilization) can be observed for non-cross-linked (NCL) samples. Although the final color varied, the cross-linked (CL) nanofibers' halochromic behavior was maintained. It was demonstrated that during cross-linking, ester groups are formed from the free carboxyl group in the cross-linked CA and the ketones present in the curcumin under acid conditions. So, CA acts as an acid catalyst to bond turmeric to the cross-linked PVA nanofibers. [ABSTRACT FROM AUTHOR]

Heterovalent B-site MgO substitution in the Nd 2 Zr 2 O 7 -system (Nd 2 Zr 2−x Mg x O 7−x) has been explored. The pyrochlores were synthesized by a polymeric sol-gel method and characterized by X-ray diffraction (XRD), Raman spectroscopy and Scanning Electron Microscopy to determine structure, phase composition and microstructure. Impedance Spectroscopy (IS) was employed to study the electrical behavior of the ceramics over the ranges 200–800 °C and under pure N 2 and O 2. The XRD showed that the solid solution limit was x > 0.02 and all the materials show a cubic Fd 3 ̅ m structure. The Raman results confirm the structural disorder created by the introduction of Mg2+ and the subsequent generation of oxygen vacancies. The IS data shows a dramatical increase of the oxide-ion conductivity when doping and that the conductivity depends strongly on the atmosphere, leading to p-type semiconductivity under pure O 2 atmosphere. The present study highlights the use of heterovalent dopants to drastically increase the oxide-ion conductivity of pyrochlore-like materials. [ABSTRACT FROM AUTHOR]

Volatile saturation influences the physicochemical behavior of magmas and is essential for the sequestration of metals in porphyry copper deposits. Tracking the evolution of volatile components (F, Cl, H2O, S) in arc systems is complicated by their mobility and tendency to rapidly re-equilibrate with late-stage melts. We demonstrate that accurate measurements of volatile concentrations in apatite offer a reliable method for identifying the occurrence of volatile saturation. Fluorine, Cl, S, and calculated OH concentrations in apatite obtained by scanning electron microscope-energy-dispersive X-ray spectroscopy and electron microprobe analysis were used to compare two end-member volcanic systems in the West Luzon Arc (Philippines): Pinatubo (a fluid-saturated analogue for porphyry copper deposits) and Taal (a barren and fluid-undersaturated comparator). Apatites from Pinatubo are S-rich (0.04-0.64 wt%) and show a progressive decrease in XCl/XOH (0.6-0.25) and an increase in XF/XCl (1.5-8) and XF/XOH (0.75-1.2) during crystallization. Modeling indicates that these changes result from efficient partitioning of Cl into a continuously saturated H2O-rich fluid, while high regions of S in apatite reflect episodic flushing by a separate S-rich flux. Little S is evident in apatites from Taal (<300 ppm), which show increasing XCl/XOH and XF/XOH together with constant XF/XCl during crystallization. This cannot be explained using an H2O-saturated model, and instead reflects fluid-undersaturated crystallization and cooling in a reduced and/or S-depleted system. Measured volatiles in apatite therefore effectively discriminate volatile-saturated and undersaturated magmatic systems, providing an important 'fertility' filter for porphyry exploration. [ABSTRACT FROM AUTHOR]

The Schiff base compound, benzyl hydrogen-4-(dimethylamino) benzylidene hydroxycarbon hydrazodithiate (BHDBHH), was investigated under continuous wave laser beam irradiation (30 mW), and its chemical properties were analyzed. The material's chemical properties were found to be affected during laser processing. We examined the chemical properties of the Schiff base using a Scanning Electron Microscope (SEM) and energy-dispersive Xray (EDX) Spectroscopy. By varying the exposure time, we discovered that longer exposure times resulted in a darker colouration of the compound, even at a low power of 30 mW. This finding led us to conclude that the compound is highly sensitive to laser exposure and can be easily diffused with a more powerful laser. The EDX test revealed a significant reduction in the sulfur element, with more than 50% of it being burned during the exposure. [ABSTRACT FROM AUTHOR]

Citrus fruits exert various beneficial health effects due to the large amount of polyphenols they contain. Citrus peels, often considered food waste, contain several health-promoting polyphenols. Among these, flavonoids have long been quantified through colorimetric assays which, if not adequately applied, can lead to conflicting results. Flavonoids possess strong antioxidant properties and can decrease circulating free radicals, thereby reducing oxidative stress phenomena. Quantifying flavonoids and properly estimating their antioxidant capacity allows us to predict plausible beneficial effects of citrus fruits on human health. The aim of this research was to analyze the advantageous phenolic compounds found in the peels of citrus fruits commonly found in the Mediterranean region. The objective was to measure their antioxidant capacity and ability to neutralize free radicals. To achieve this purpose, UV-visible spectrophotometric analyses, liquid chromatography (LC) and Electron Paramagnetic Spectroscopy (EPR) were utilized and compared, finally suggesting an innovative approach for assessing the overall flavonoid content by the nitrite-aluminum assay. HPLC data demonstrated that hesperidin was the most abundant flavonoid in all peel extracts except for orange peels, in which naringin was the predominant flavonoid. The total flavonoid content was greater than 1.3 mg/mL in all extracts, with tangerine and orange yielding the best results. Citrus peel polyphenols exerted strong antioxidant and free radical scavenging effects, inhibiting up to 75% of the free radicals used as reference in the EPR analyses. [ABSTRACT FROM AUTHOR]

Cobalt diphosphides (CoP2) show a high theoretical capacity and hold great promise as anode materials for lithium-ion batteries (LIBs). However, the large variation in the volume and structure of CoP2 caused during lithium-ion insertion and extraction results in electrode fragmentation and a compromised solid electrolyte interface, ultimately leading to poor cycling performance. Herein, a composite of CoP2 nanoparticles encapsulated in carbon matrix has been successfully synthesized by carbonization of Co-MOF-based zeolitic imidazolate frameworks (ZIF-67) and sequential phosphorization and further wrapped in graphene oxide (CoP2@C@GO). The formation of CoP2 was confirmed by X-ray diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The morphology of CoP2@C with and without GO wrapping was examined by scanning electron microscopy and transmission electron spectroscopy. It was demonstrated that the decoration of GO significantly reduces the polarization of CoP2@C electrodes, enhancing their charge capacity and cycling stability as an anode material for LIBs. After 200 cycles, they deliver a capacity of 450 mAh·g−1. [ABSTRACT FROM AUTHOR]

The resistivity behaviour and voltage-dependent dynamic conductance of Nd 0.6 Sr 0.4 CoO 3 nanomaterials were studied with respect to two different grain sizes (∼ 55 nm and ∼ 140 nm). Three distinct regions were observed in the temperature-dependent resistivity ( ρ - T ) graph. An upturn in the ρ - T curve was observed below 100 K, which was enhanced with decreasing grain size. This enhancement was investigated, and the analysis suggests that electron–electron interaction plays a key role. We probed the transport mechanism using the isothermal current–voltage (I–V) characteristics. Non-linear dynamic conductance was found for both samples. A temperature-dependent non-linear exponent suggests three types of current transport mechanisms. A voltage-driven crossover from inelastic tunnelling via localized states to direct elastic tunnelling through the grain boundary was observed around the critical region for metal insulator transition. [ABSTRACT FROM AUTHOR]

This study investigates the effects of electrohydrodynamic (EHD) drying technology on the drying kinetics, microstructure, quality, and nutritional components of carrots, along with conducting experiments on EHD drying under different voltage gradients. The experimental results showed that EHD drying technology could significantly increase the drying rate and the effective moisture diffusion coefficient. Within a certain range, the drying rate was directly proportional to the voltage. When the range was exceeded, the increase in voltage had a minimal effect on the drying rate. In terms of quality, the EHD drying group's color, shrinkage rate, and rehydration performance were superior to the control group, and different voltages had no significant effect on the shrinkage rate and rehydration performance. The retention of carotenoids in the EHD drying group was 1.58 to 2 times that of the control group. EHD drying had a negative impact on the total phenolic content and vitamin A content of dried carrot slices. Based on the results of infrared spectroscopy and scanning electron microscopy (SEM), the dehydrated carrot slices showed wrinkling due to water loss, with numerous pores, a generally intact structure, and retained functional groups. EHD drying had a significant impact on the secondary structure of proteins, where an increase in voltage led to an increase in disordered structure, with a smaller proportion of disordered structure in the lower voltage group compared to the control group, and a similar proportion of disordered structure between the higher voltage group and the control group. Results from low-field nuclear magnetic resonance (NMR) showed that EHD drying could retain more bound water compared to the control group, with the best retention of cellular bound water at a voltage of 26 kV and the best retention of cellular immobilized water at a voltage of 38 kV, indicating the superiority of EHD drying in preserving cellular structure. This study provided a theoretical basis and experimental foundation for the application of electrohydrodynamic drying technology to carrot drying, and promoted the practical application of EHD drying technology. [ABSTRACT FROM AUTHOR]

High levels of cobalt and chromium ions were detected in the bodies of multiple recipients of modular cobalt chrome molybdenum metal-on-metal hip implants, necessitating the revision of their implants. A forensic engineering investigation of provided discovery documents and existing literature regarding the design, manufacturing, and clinical testing of these modular hip implants was performed. The investigation revealed that the modular interfaces of the implant allowed for micromotion to induce mechanically assisted crevice corrosion at these surfaces. The debris from this corrosion resulted in the release of metal ions into the bodies of the users, forming pseudotumors and compromising the user's health and wellbeing. The effect of this corrosion was enhanced by the galvanic couple that existed between the modular components of the implant. In addition, scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) analysis identified silicon carbide (SiC) and aluminum oxide (AL2O3) particles left behind from polishing, which were embedded in the ball and liners. These particles accelerated the wear of the hip implant and further exacerbated the release of metal ions. The designers of future hip implants should take care in preventing the occurrence of the above-stated factors. [ABSTRACT FROM AUTHOR]

The development of new efficient photocatalysts is critical for a variety of applications including water purification and water splitting. Unfortunately, because TiO2 has a wide band gap, the photocatalytic applications of TiO2 NTAs are restricted to light in the ultraviolet (UV) range. Nanosized barium carbonate nanoparticles were prepared by a precipitation method at relatively low temperatures. The prepared samples were characterized by X-ray diffraction, UV-Visible diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy techniques. The nanocomposite exhibited a strong photocatalytic activity for decomposition of Crystal violet (CV) under visible light irradiation. The influences of catalyst amount, initial Crystal violet concentrations, pH of the reaction solution and different anions on CV decolorization and degradation reaction kinetics were investigated. The dye could be decolorized more efficiently in acidic media than alkaline media. Furthermore, the photocatalyst indicated phenomenal strength after four response cycles. At last, the conceivable component for the action upgrade was examined in detail. [ABSTRACT FROM AUTHOR]

The International Standard ISO 18115‐1 on terminology in surface chemical analysis has been revised with clarifications, modifications, and deletions to more than 70 terms and with the addition of more than 50 terms in response to trends, issues, and needs identified by the surface analysis community. This revision adds terminology and concepts associated with emerging methods such as atom probe tomography, near ambient pressure XPS, and hard X‐ray photoelectron spectroscopy. It includes 25 new and revised terms to ensure that the description of resolution is consistent across all surface analysis methods. The 630 terms in the document cover words or phrases used in describing the samples, instruments, and concepts involved in surface chemical analysis. The terms have been collated into subject specific sections to ensure that related terms can be found easily. [ABSTRACT FROM AUTHOR]

In this work, we studied atomic self-diffusion and structural phase transformation in a single phase iron mononitride (FeN) thin film deposited at an optimized substrate temperature (Ts) of 423 K. At this Ts, the FeN film exhibits a tetrahedral coordination between Fe and N atoms (ZnS-type structure with a lattice parameter of 4.28 Å). The structure of the FeN film was studied by combining x-ray diffraction with Fe and N K-edge x-ray absorption spectroscopy and conversion electron Mössbauer spectroscopy measurements. Self-diffusion of Fe and N was measured using secondary ion mass spectroscopy depth profiling in trilayer structures: [FeN(50 nm)/ 57 FeN(2 nm)/FeN(50 nm)] and [FeN(50 nm)/Fe 15 N(2 nm)/FeN(50 nm)] deposited on an amorphous quartz substrate using reactive magnetron sputtering. It was found that atomic self-diffusion is strongly associated with thermal stability. Before reaching the phase decomposition temperature, the self-diffusion of N was found to be slower than Fe. Upon phase decomposition, both Fe and N diffuse rapidly, and at this stage, the self-diffusion of N takes over Fe. Within the thermally stable state, slower N diffusion indicates that Fe–N bonds are stronger than Fe–Fe bonds in FeN. This behavior was predicted theoretically and has been evidenced in this work. [ABSTRACT FROM AUTHOR]

Lead sulfide (PbS) nano-domain (ND) thin layers were grown by a chemical bath deposition technique on a heavily doped n-type GaAs substrate forming a heterojunction. The PbS NDs' absorption was blue shifted from its original wavelength due to the quantum confinement effect (by controling their sizes below the Bohr radius) to sense short wavelength infrared (SWIR) light (ranging between 1200 and 1800 nm). In order to assess the electrical properties of the PbS ND based layers to be used as a SWIR detector, we performed electrical measurements that included current–voltage (I–V), capacitance–voltage (C–V), electron impedance spectroscopy (EIS), and transmission electron microscopy (TEM). The I–V measurements showed hysteresis behavior that was found to be imposed by the high trap concentration within the PbS NDs and at the layer interfaces. The hysteresis that was demonstrated during the electrical measurement is explained by the slow filling of the trap within the PbS ND thin layer. In order to reduce the trap density, we performed a thermal treatment at 150 ° C for 30 min prior to the electrical measurements. Using C–V measurements, we expected to find a reduction in the capacitance due to the decrease of the trap density after the thermal treatment. However, we discovered an increase in the capacitance, where temperature-dependent I–V measurements revealed an additional slow charging mechanism in series with the heterojunction. We found that this can be attributed to the generation of a thin isolation layer at the interface between the PbS-NDs layer and the GaAs substrate that also contains interface traps induced by the thermal treatment that was performed in an air atmosphere. We corroborated our assumption by performing EIS measurements and TEM analysis, which showed the generation of a thin isolation layer at the PbS/GaAs interface. [ABSTRACT FROM AUTHOR]

Abstract Provision of atomic hydrogen by hydrogen dissociation catalysts only moderately accelerates the hydrogenation rate of magnesium. They shed light on this well‐known but technically challenging fact through a combined approach using an unconventional surface science technique together with Density Functional Theory (DFT) calculations. The calculations demonstrate the drastic electronic structure changes during transformation of Mg to MgH2, which make fractional hydrogen coverage on the surface, as well as substoichiometric hydrogen content in the bulk energetically unfavorable. Reflecting Electron Energy Loss Spectroscopy (REELS) is used to measure the surface and bulk plasmon during hydrogen sorption in magnesium. The measurements show that the hydrogenation proceeds via the growth of magnesium hydride without the presence of chemisorbed hydrogen on the metallic magnesium surface exactly as indicated by the calculations. This is due to the low stability of sub‐stoichiometric amounts of chemisorbed H correlating with the unfavorable charge state of Mg. They are merely bound to the unchanged adjacent Mg layers, thereby explaining the failure of classical hydrogenation catalysts, which effectively only hydrogenate Mg in their direct vicinity. The acceleration of hydrogen sorption kinetics in Mg must affect the polarization in the interface between Mg and MgH2 during hydrogenation.