Fourier Transform Infrared Spectroscopy Measurements Research Articles

MANUSCRIPT Local Crowd, Local Probe: Strengths and Drawbacks of Azidohomoalanine as a Site-Specific Crowding Probe.

Every residue on a protein can be characterized by its interaction with water, in lack or in excess, as water is the matrix of biological systems. Infrared spectroscopy and the implementation of local azidohomoalanine (AHA) probes allow us to move beyond an ensemble or surface-driven conceptualization of water behavior and toward a granular, site-specific picture. In this paper, we examined the role of crowding in modulating both global and local behavior on the β-hairpin, TrpZip2 using a combination of Fourier-transform infrared spectroscopy (FTIR) spectroscopy, two-dimensional infrared (2D IR) spectroscopy, and molecular dynamics simulations. We found that, at the amino acid level, crowding drove dehydration of both sheet and turn peptide sites as well as free AHA. However, the subpicosecond dynamics showed highly individualized responses based on the local environment. Interestingly, while steady-state FTIR measurements revealed similar responses at the amino-acid level to hard versus soft crowding (dehydration), we found that PEG and glucose had opposite stabilizing and destabilizing effects on the protein secondary structure, emphasizing an important distinction in understanding the impact of crowding on protein structure as well as the role of crowding across length scales.

Physicochemical characterization of rice straw before and after alkali-assist photocatalytic pretreatment: a comparative analysis.

The potential of alkali-assist photocatalytic (AAP) pretreatment to overcome the recalcitrant nature of lignocellulose biomass, i.e. rice straw (RS), was investigated in the present study. Box-Behenken Design (BBD) using standard response surface methodology (RSM) approach was considered to obtain optimal conditions for maximum delignification. The model was designed with three variables: alkali concentration (NaOH, 0-3% w/v), photocatalyst (TiO2 NPs (titania nanoparticles), 0-1g/L) and pretreatment time (30-240min). The availability of cellulose was increased by 96.73%, while the concentration of lignin and hemicellulose decreased by 73.89%, and 71.79%, respectively, at a combination of 1.5% NaOH, 0.5g/L TiO2 NPsand 135 min pretreatment time. The structural and morphological alterations in the RS were assessed via Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) both before and after AAPpretreatment. The FTIR measurement indicated that the original RS included a significant quantity of lignin, which was eliminated after the pretreatment procedure. The XRD pattern demonstrates that cellulose crystallinity is significantly affected by the pretreatment. The SEM analysis revealed structural distortion and surface porosity from the pretreatment procedure.

Bottom-up Growth of Convex Sphere with Adjustable Cu(0)/Cu(I) Interfaces for Effective C2 Production from CO2 Electroreduction.

One challenge confronting the Cu2O catalysts in the electrocatalysis of carbon dioxide reduction reaction (CO2RR) is the reduction of active Cu(I) species, resulting in low selectivity and quick deactivation. In this study, we for the first time introduce a bottom-up growth of convex sphere with adjustable Cu(0)/Cu(I) interfaces (Cux@Cu2O convex spheres). Interestingly, the interfaces are dynamically modulated by varying hydrothermal time, thus regulating the conversion of C1 and C2 products. In particular, the 4 h hydrothermal treatment applied to Cu0.25@Cu2O convex sphere with the favorable Cu(0)/Cu(I) interface results in the highest selectivity for C2 products (90.5%). In situ Fourier-transform infrared spectroscopy measurements and density functional theory calculations reveal that the Cu(0)/Cu(I) interface lowers the energy barrier for the production of ethylene and ethanol while increasing the coverage of localized *CO adsorbate for increased dimerization. This work establishes a novel approach for transforming the state of valence-sensitive electrocatalysts into high-value energy-related engineering products.

CHARACTERIZATION AND OPTICAL STUDIES OF ION BEAM-IRRADIATED CA/PANI COMPOSITE MATERIALS

In the present research, cellulose acetate (CA) and polyaniline (PANI) were combined to form CA/PANI films using the solution-casting method. This research aims to provide novel optical behavior for irradiated flexible CA/PANI sheets to be utilized in high-performing optical devices. The Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) were employed to effectively produce the CA/PANI samples. The argon fluence of [Formula: see text], [Formula: see text], and [Formula: see text][Formula: see text]ions/cm2 have been added to these films. The FTIR and XRD measurements showed that the ion treatment of CA/PANI films altered their functions and crystalline compositions. This indicates that the CA/PANI films were successfully prepared. The optical properties were measured using the UV–Vis technique in a wavelength of 200–1150[Formula: see text]nm. The Tauc relationship was used to estimate the band gap and Urbach energies of both bombarded and untreated films. In response to [Formula: see text], [Formula: see text], and [Formula: see text][Formula: see text]ions/cm2, CA/PANI exhibits a drop in band gap from 4.92[Formula: see text]eV to 4.45, 4.31, and 4.20[Formula: see text]eV, respectively. According to these results, the optical performance of the irradiated CA/PANI composite films was modified to be used in optoelectronics.

CPD model prediction of oil sand pyrolysis based on structural parameters from 13C NMR and FTIR measurements

Here, carbon-13 nuclear magnetic resonance spectroscopy (13C NMR) and Fourier transform infrared spectroscopy (FTIR) techniques were used to study the chemical structure characteristics of oil sand and its pyrolysis oil. The FTIR results showed that the values of the CH2/CH3 ratio, A-factor, and DOC1 of the pyrolysis oil decreased during the pyrolysis process, while the C-factor showed a maximum value with increasing pyrolysis temperature. The 13C NMR results showed that methylides and methylides were mainly contributed to oil production. The aliphatic chain in the pyrolysis oil has little alterations during pyrolysis, while the extent of aromatic ring substitution increases from 0.46 to 0.58. Furthermore, a correlation was obtained between the chemical structure of oil and the pyrolysis product yields of oil sand. Moreover, using chemical structure parameters investigated with FTIR and 13C NMR and kinetic parameters based on the thermogravimetric data, the chemical percolation devolatilization (CPD) model was applied to simulate the pyrolysis of oil sand. The results showed that the simulated results for tar and light gas were in good agreement with the experimental data, while those for char underpredicted the experimental data. Overall, the CPD model can effectively predict the pyrolysis of oil sand.

Green synthesis and characterisation of spherical structure Ag/Fe2O3/TiO2 nanocomposite using acacia in the presence of neem and tulsi oils

Abstract In this study, tulsi and neem oils were used to effectively synthesise Ag/Fe2O3/TiO2 nanocomposite utilising environmentally friendly methods. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) methods were used to characterise the green synthesised nanocomposite. The triangle-spherical shaped nanoparticles (NPs) with an average size of 26–42 nm were shown by XRD and SEM investigations to be crystalline in Ag/Fe2O3/TiO2 nanocomposite, respectively. Additionally, the dynamic light scattering histogram was used to quantify the size distribution of these NPs, and the results were consistent with those of the SEM picture, having an approximate element size of 28 nm. The Ag/Fe2O3/TiO2 nanocomposite is reduced and stabilised as a result of functional groups present in acacia, and neem, and tulsi oils, as shown by FT-IR measurements. In a nutshell, this method offers a quick, affordable, and environmentally safe technique to create NPs without the use of potentially dangerous chemical agents.

Reducing Time and Costs of FT-IR Studies of the Effect of SiNx, Dopants, and Emitter on Hydrogen Species in Si Wafers and Solar Cell Structures

Accurately measuring the hydrogen content in silicon (Si) solar cells is essential due to its connection to surface degradation and light and elevated temperature induced degradation (LeTID). Fourier Transform-Infrared (FT-IR) spectroscopy provides a quantitative technique for determining the content of various hydrogen species in Si wafers that have undergone various process steps. In this study, we examine both the effect of a silicon nitride (SiNx:H) layer during FT-IR spectroscopic measurements on hydrogen species, as well as the impact of an emitter present during firing on the amount of hydrogen introduced into Si wafers. We find that the presence of SiNx:H during measurements has negligible effects on the measured hydrogen species, potentially simplifying the preparation steps for FT-IR. For the emitter investigation we analyze boron (B)- and gallium (Ga)-doped p-type wafers to detect H-B, H-Ga, Oi-H2, and H2. We observe that hydrogen species initially present in B- and Ga-doped Si wafers differ significantly. Only H-Ga is detected in Ga-doped wafers, while H-B, Oi-H2, and H2 signals are measured in B-doped wafers. Moreover, we cannot confirm an increased release of H through the emitter into the bulk during the firing process. Finally, we conduct measurements at different temperatures and confirm that cryogenic temperatures are more effective for detecting H-B and H2 with concentrations in the 1014 cm-3 range. Nevertheless, useful spectra can still be obtained at liquid nitrogen (N2) temperatures.

Transitioning from Methanol to Olefins (MTO) toward a Tandem CO2 Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes.

The tandem CO2 hydrogenation to hydrocarbons over mixed metal oxide/zeolite catalysts (OXZEO) is an efficient way of producing value-added hydrocarbons (platform chemicals and fuels) directly from CO2via methanol intermediate in a single reactor. In this contribution, two MAPO-18 zeotypes (M = Mg, Si) were tested and their performance was compared under methanol-to-olefins (MTO) conditions (350 °C, PCH3OH = 0.04 bar, 6.5 gCH3OH h-1 g-1), methanol/CO/H2 cofeed conditions (350 °C, PCH3OH/PCO/PH2 = 1:7.3:21.7 bar, 2.5 gCH3OH h-1 g-1), and tandem CO2 hydrogenation-to-olefin conditions (350 °C, PCO2/PH2 = 7.5:22.5 bar, 1.4-12.0 gMAPO-18 h molCO2-1). In the latter case, the zeotypes were mixed with a fixed amount of ZnO:ZrO2 catalyst, well-known for the conversion of CO2/H2 to methanol. Focus was set on the methanol conversion activity, product selectivity, and performance stability with time-on-stream. In situ and ex situ Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), solid-state nuclear magnetic resonance (NMR), sorption experiments, and ab initio molecular dynamics (AIMD) calculations were performed to correlate material performance with material characteristics. The catalytic tests demonstrated the better performance of MgAPO-18 versus SAPO-18 at MTO conditions, the much superior performance of MgAPO-18 under methanol/CO/H2 cofeeds, and yet the increasingly similar performance of the two materials under tandem conditions upon increasing the zeotype-to-oxide ratio in the tandem catalyst bed. In situ FT-IR measurements coupled with AIMD calculations revealed differences in the MTO initiation mechanism between the two materials. SAPO-18 promoted initial CO2 formation, indicative of a formaldehyde-based decarboxylation mechanism, while CO and ketene were the main constituents of the initiation pool in MgAPO-18, suggesting a decarbonylation mechanism. Under tandem CO2 hydrogenation conditions, the presence of high water concentrations and low methanol partial pressure in the reaction medium led to lower, and increasingly similar, methanol turnover frequencies for the zeotypes. Despite both MAPO-18 zeotypes showing signs of activity loss upon storage due to the interaction of the sites with ambient humidity, they presented a remarkable stability after reaching steady state under tandem reaction conditions and after steaming and regeneration cycles at high temperatures. Water adsorption experiments at room temperature confirmed this observation. The faster activity loss observed in the Mg version is assigned to its harder Mg2+-ion character and the higher concentration of CHA defects in the AEI structure, identified by solid-state NMR and XRD. The low stability of a MgAPO-34 zeotype (CHA structure) upon storage corroborated the relationship between CHA defects and instability.

A High-Performance Cr2O3/CaCO3 Nanocomposite Catalyst for Rapid Hydrogen Generation from NaBH4.

This study aims to prepare new nanocomposites consisting of Cr2O3/CaCO3 as a catalyst for improved hydrogen production from NaBH4 methanolysis. The new nanocomposite possesses nanoparticles with the compositional formula Cr2-xCaxO3 (x = 0, 0.3, and 0.6). These samples were prepared using the sol-gel method, which comprises gelatin fuel. The structure of the new composites was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, environmental scanning electron microscopy (ESEM), and X-ray spectroscopy (XPS). The XRD data showed the rhombohedral crystallinity of the studied samples, and the average crystal size was 25 nm. The FTIR measurements represented the absorption bands of Cr2O3 and CaO. The ESEM micrographs of the Cr2O3 showed the spherical shape of the Cr2O3 nanoparticles. The XPS measurements proved the desired oxidation states of the Cr2-xCaxO3 nanoparticles. The optical band gap of Cr2O3 is 3.0 eV, and calcium doping causes a reduction to 2.5 and 1.3 eV at 15.0 and 30.0% doping ratios. The methanolysis of NaBH4 involved accelerated H2 production when using Cr2-xCaxO3 as a catalyst. Furthermore, the Cr1.7Ca0.3O3 catalyst had the highest hydrogen generation rate, with a value of 12,750 mL/g/min.

The Performance and Reaction Mechanism of Untreated Steel Slag Used as a Microexpanding Agent in Fly Ash-Based Geopolymers

Steel slag is an industrial by-product of the steelmaking process, which is under-utilized and of low value due to its characteristics. Alkali-activated technology offers the possibility of high utilization and increased value of steel slag. A geopolymer composition was composed of steel slag, fly ash, and calcium hydroxide. Four experimental groups utilizing steel slag to substitute fly ash are established based on varying replacement levels: 35%, 40%, 45%, and 50% by mass. The final samples were characterized by compressive strength tests, and Fourier-transform infrared spectroscopy measurements, thermogravimetric measurements, scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, and mercury intrusion porosimetry were used to investigate the chemical composition and microstructure of the final products. Higher steel slag/fly ash ratios lead to a lower bulk density and lower compressive strength. The compressive strength ranges from 3.7 MPa to 5.6 MPa, and the bulk density ranges from 0.85 g/cm3 to 1.13 g/cm3. Microstructural and energy-dispersive X-ray spectroscopy analyses show that the final geopolymer products were a type of composite consisting of both calcium aluminate silicate hydrate and sodium aluminate silicate hydrate, with the unreacted crystalline phases acting as fillers.

Influences of magnesium ions in water on gelatinization characteristics of starch and its flocculation behaviors on particles

It is inevitable for the occurrence or built-ups of disturbing cations, especially Ca<sup>2+</sup> or Mg<sup>2+</sup> ions, in process water during the flotation of iron oxides by using starch as flocculants. In addition to alkali concentrations and temperature, water quality could have an essential role in changing the physicochemical properties of the starch solution and consequently disturbing its flocculation performance on particles. This study aims to identify the effects of magnesium ions on the gelatinization characteristics of starch and its flocculation properties on particles through a series of tests, such as flotation tests, settling tests, size analyses, zeta potentials, powder contact angle, Fourier Transform Infra-Red (FTIR) and X-ray Photoelectron Spectroscopy (XPS) measurement. All results show that magnesium ions at ≤ 4 mmol/L have a positive role due to enlarging the sizes of the particle flocs and accelerating their settling rates. The occurrence of Mg<sup>2+</sup> ions at higher concentrations during starch gelatinization only obtains a starch sol-gel with entangled configurations and preoccupied active sites, resulting in the slower settling rate of the particle flocs and less hydrophilicity on mineral surfaces. It could be attributed to the cross-link interactions of magnesium-based precipitates with the acidic groups, especially carboxyl groups on the starch remnants. The suitable acid/base interactions between Mg(OH)<sub>2</sub>/MgCO<sub>3</sub> compounds with these groups in the starch suspension could be beneficial for enhancing the flocculation of hematite as they could build bridges among the pieces and enlarge their sizes as a “load carrier” for aggregation with minerals. However, too much cross-linking could re-entangle the remnants, block their adsorption sites on mineral surfaces, and eventually, weaken the flocculation capacity of starch.

Structural and magnetic properties of Fe and Ni co-doped SnO2 nanoparticles prepared by co-precipitation method

In this research work Fe and Ni co-doped Tin oxide (SnO2) nanoparticles have been prepared by co-precipitation method. The samples were prepared at various combination of Fe and Ni from 0% up to 10%. The produced nanoparticles were studied by x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV–vis Spectrophotometer, Fourier Transformation Infrared Spectroscopy (FTIR) and Vibrating Sample Magnetometer (VSM). The XRD study reveals the formation of rutile structure of the undoped and doped SnO2 nanoparticles with the average crystallite size of 1.5–10.8 nm. Metal oxide bonding is confirmed through FTIR measurement. Optical band gap redshift (3.9 to 3.64 eV) with doping of Fe and Ni atom is observed. SEM image confirms the formation of spheroidal nanoparticles and size of the nanoparticle varies from 36 to 15 nm. The VSM study shows the ferromagnetic phase transition at 7% Ni, Fe doped SnO2 nanoparticles. This ferromagnetism arises for the oxygen vacancies and defect states. Further, increase of doping concentration of 10%, nanoparticles show the phase transition from ferromagnetic to paramagnetic. Such transition can be applicable in hyperthermia treatment and memory devices.

Preparation and Characterization of Demineralised Bone Matrix from Fish Waste

Due to its osteoinductive and osteoconductive qualities, demineralized bone matrix (DBM) is a desirable biomaterial frequently utilised in tissue engineering and regenerative medicine. As a sustainable alternative to conventional sources like mammalian bones, we set out to create and characterise DBM made from fish waste, primarily fish bones. Several methodologies were used to thoroughly characterise the generated DBM. The chemical composition was examined using Fourier-transform infrared spectroscopy (FTIR), which also served to confirm the removal of mineral components. In order to analyse the DBM's microstructure and surface morphology, scanning electron microscopy (SEM) was performed. According to FTIR measurement, the DBM showed a considerable decrease in mineral content, demonstrating successful demineralization. A porous structure with linked pores was visible in SEM images, allowing for nutrition diffusion and cell penetration. Additionally, the DBM's biological characteristics were assessed. Studies using in vitro cell cultures showed that the DBM might help human mesenchymal stem cells adhere, proliferate, and differentiate into osteogenic cells. Through in vivo animal studies, the osteoinductive ability of the DBM was evaluated. The implanted DBM stimulated new bone production in a rat calvarial deficiency model. As a result of our study's successful preparation and characterisation of DBM from fish waste, we now have a reliable and affordable supply for this important biomaterial. Positive characteristics of the demineralized fish bone matrix included reduced mineral content, porosity structure, and osteoinductive capability. These results demonstrate the possibility of DBM generated from fish waste as a promising substitute for bone regeneration applications.

Highly efficient CO2 and propylene oxide co-polymerization using Zn glutarate/Zn-Cr double metal cyanide composite catalyst

A highly active zinc glutarate-double metal cyanide (DMC) composite catalyst (ZnGA/Zn-CrDMC) was designed for the carbon dioxide (CO2) and propylene oxide (PO) copolymerization reaction. The composite catalyst was synthesized in a rheological phase reaction and characterized using Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The synthesized composite catalysed the solvent free reactions of PO and CO2 to afford biodegradable polypropylene carbonate (PPC) copolymer. 1H NMR,13C NMR, FT-IR and ESI-TOF mass spectrometry measurements were employed to confirm the characteristics of the PPC produced. Under optimal reaction conditions (50 bar CO2, 70 °C, 24 h), the ZnGA-Zn3[Cr(CN)6]2 composite displayed higher catalytic activities in the copolymerization reactions than the individual catalysts. The ZnGA:Zn3[Cr(CN)6]2 ratio of 15:1 gave PPC yield of 47.9 g polymer/g cat compared to ZnGA that produced 42.6 g polymer/ g cat in 24 h. In addition, the PPC produced from the composite catalyst displayed higher carbonate linkage content (Fc = 85.4 %) compared to the value of Fc = 33.9 %. obtained using the Zn3[Cr(CN)6]2 catalyst. Similaly, the composite catalsyt produced PPC with molecular weight of 4200 g/mol and narrow polydispersity index of 2.2. The resultant PPC copolymer displayed good thermal stability, exhibiting a high degradation temperatures (TGA-10%) of 229 °C and complete decomposition at 350 °C.

New Insights into the Chemical Compatibility of Nitrochitosan with Potential Energetic Molecules

This study provides new insights into the compatibility of a promising energetic polysaccharide, called nitrochitosan (NCS), with energy-rich ammonium perchlorate (AP), ammonium nitrate (AN), and hydrazine 3-nitro-1,2,4-triazol-5-one (HNTO) molecules, in order to survey their application prospects in solid rocket propellants and explosives. For this purpose, differential scanning calorimetry (DSC) and thermogravimetric (TGA) analyses were carried out to accurately evaluate the chemical compatibility of NCS with the selected energetic molecules following the STANAG 4147 criterion. Fourier transform infrared spectroscopy (FTIR), as a non-thermal complementary technique, was also performed to further elucidate the eventual structural alterations occurring in the physical mixtures (NCS/AP, NCS/AN, and NCS/HNTO). Based on DSC results, the maximum exothermic peak temperature difference between NCS (Tpeak = 164.7 °C) and the as-prepared NCS/AP (Tpeak = 164.3 °C), NCS/AN (Tpeak = 204.3 °C), and NCS/HNTO (Tpeak = 197.0 °C) admixtures is found to be lower than 4 °C. Moreover, TGA experiments showed that the observed mass losses of the physical mixtures are lower than the sum of the weight losses of their respective individual compounds. Therefore, thermal results demonstrated the excellent chemical compatibility of NCS with the corresponding energetic molecules. In addition, FTIR measurements highlighted the absence of chemical interactions between NCS and the selected AP, AN, and HNTO. Therefore, a deep investigation into the characteristics of such energetic composites and their real-world applications will be among the main focuses of the postulated next stage of research.

Interaction of Cold Atmospheric Pressure Plasma with Soybean Seeds: Effect on Germination and DNA, Seed Surface Characteristics and Plasma Diagnostics

This study investigates the relation between cold atmospheric pressure plasma (CAPP) effect on seeds and the plasma parameters. As a source of CAPP, the diffuse coplanar surface barrier discharge (DCSBD) generated in nitrogen, ambient air, and oxygen at atmospheric pressure was used. Results of germination and the level of DNA damage of soybean seeds (Glycine max L.) treated in plasma and plasma gaseous products showed that the most advantageous is the use of ambient air plasma treatment. The water contact angle (WCA) of samples treated directly in plasma was significantly smaller than that of samples treated with gaseous products. Using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), we did not observe significant changes between the spectra of individual samples, what indicates that there is no damage on the surface of the samples during the treatment, only the binding of polar groups. The method of optical emission spectroscopy (OES) and Fourier transform infrared spectroscopy (FTIR) were used to study the plasma parameters. The most radiant system observed in ambient air and nitrogen plasma is the second positive system of nitrogen N2C3∏u→B3∏g\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{N}}_{2} \\left( {{\ ext{C}}^{3} \\prod _{{\ ext{u}}} \ o {\ ext{B}}^{3} \\prod _{{\ ext{g}}} } \\right)$$\\end{document}. FTIR measurements showed the presence of reactive oxygen and nitrogen species O3, NO2, N2O, NO, HNO2 depending on the working gas. Finally, it can be assumed that the positive effect of plasma on the seed is caused not only by the individual components of the plasma, but also by their synergistic effect, while the ratio of the individual active particles as well as the plasma exposure to the seeds are important.

Operando FTIR-ATR with molecular dynamic simulations to understand the diffusion mechanism of waste tire-derived pyrolytic oil for asphalt self-healing

Recent research proves that pyrolytic oils from waste tires are effective in restoring the chemical and rheological properties of aged asphalt binders. Nonetheless, the role of oil-binder molecular interactions and bindeŕs aging degree on the diffusional behavior of the pyro-oils is still unclear. In this study, authors propose integrating operando Fourier Transformed Infrared Spectroscopy (FTIR) measurements with molecular dynamics (MD) simulations as a novel approach to unravel the diffusion mechanisms of pyro-oils in asphalt binders with self-healing purposes. The produced pyro-oils contains aliphatic and single-ring alkyl aromatic compounds as the most abundant species (ca. 80%). The operando FTIR measurements were correlated by a Fickian model, resulting in diffusion coefficients (D0) between 10-12 and 10-11 m2s−1. Moreover, MD simulations, with a molecular model of aged asphalt containing benzylic rings, sulfoxides, and hydroxyl functional groups, demonstrated that interactions of functional groups in the pyro-oil with the binder, hinder the diffusion behavior of the pyro-oil. The D0 estimated from the MD simulations agreed with those calculated from experimental data and previous reports for petro- and bio-derived rejuvenators. The predictive performance of the MD simulations developed in this study confirms to design of more resilient self-healing asphalt binders using a bottom-up strategy.

Heterogeneous photochemical conversion of chlorobenzene on γ-Al2O3: A chamber experiment study

Atmospheric photochemical conversion of chlorinated volatile organic compounds (CVOCs) is crucial for secondary aerosol formation and tropospheric chlorine chemistry. However, their corresponding conversion pathways and the reaction products are lack of sufficient exploration. Herein, the photochemical conversion of chlorobenzene (CB) on the mineral γ-Al2O3 particulates was chosen as a model reaction to unveil the atmospheric chemistry of CVOCs. Chamber experiments were performed to determine the decay rates of CB with/without SO2 or NH3 under light irradiation. Reaction products were evaluated, along with the in situ diffuse reflectance infrared Fourier transform spectroscopy measurements, to explore the CB conversion pathways under different conditions. We showed that the CB could be greatly degraded by γ-Al2O3 under light irradiation, and the added SO2 significantly inhibited this conversion owing to surface acidification. However, the presence of NH3 was shown to facilitate the CB conversion by immobilizing Cl− as NH4Cl, and recovering surface oxygen vacancies for oxygen activation. In particular, we found that polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) could be generated from the photochemical CB conversion over γ-Al2O3, regardless of SO2 or NH3 coexistence, indicating a potential origin of PCDD/Fs on the atmospheric particulates from the heterogeneous photochemical CVOC conversion.

Optical, magnetic, and photoluminescence properties of Cr/Mn-doped ZnO nanoparticles synthesised by solution combustion method

In this study, we investigated the structural, optical, photoluminescence, and magnetic characteristics of pristine and Cr/Mn-doped ZnO nanoparticles prepared via the solution combustion method. The prepared nanoparticles exhibited a monophasic hexagonal structure. The successful incorporation of Cr/Mn elements into the ZnO lattice is reflected in the X-ray photoelectron spectroscopy, UV-vis. absorbance spectroscopy and Fourier-transform infrared spectroscopy measurements. Further, the photoluminescence intensity of ZnO nanoparticles changed upon Cr/Mn-doping due to the changed defect structure of nanoparticles. Furthermore, both pristine and Cr/Mn-doped ZnO nanoparticles revealed the ferromagnetic behaviour, wherein the doping of Cr/Mn enhanced the ferromagnetic characteristics. Overall, our results divulged that doping ZnO nanoparticles with appropriate combination of transition elements would leads to unearth fascinating optical and magnetic properties.

Application of Fourier Transform InfraRed spectroscopy of machine learning with Support Vector Machine and principal components analysis to detect biochemical changes in dried serum of patients with primary myelofibrosis

Primary myelofibrosis (PM) is a myeloproliferative neoplasm characterized by stem cell-derived clonal neoplasms. Several factors are involved in diagnosing PM, including physical examination, peripheral blood findings, bone marrow morphology, cytogenetics, and molecular markers. Commonly gene mutations are used. Also, these gene mutations exist in other diseases, such as polycythemia vera and essential thrombocythemia. Hence, understanding the molecular mechanism and finding disease-related biomarker characteristics only for PM is crucial for the treatment and survival rate. For this purpose, blood samples of PM (n = 85) vs. healthy controls (n = 45) were collected for biochemical analysis, and, for the first time, Fourier Transform InfraRed (FTIR) spectroscopy measurement of dried PM and healthy patients' blood serum was analyzed. A Support Vector Machine (SVM) model with optimized hyperparameters was constructed using the grid search (GS) method. Then, the FTIR spectra of the biomolecular components of blood serum from PM patients were compared to those from healthy individuals using Principal Components Analysis (PCA). Also, an analysis of the rate of change of FTIR spectra absorption was studied. The results showed that PM patients have higher amounts of phospholipids and proteins and a lower amount of H-O=H vibrations which was visible. The PCA results indicated that it is possible to differentiate between dried blood serum samples collected from PM patients and healthy individuals. The Grid Search Support Vector Machine (GS-SVM) model showed that the prediction accuracy ranged from 0.923 to 1.00 depending on the FTIR range analyzed.Furthermore, it was shown that the ratio between α-helix and β-sheet structures in proteins is 1.5 times higher in PM than in control people. The vibrations associated with the CO bond and the amide III region of proteins showed the highest probability value, indicating that these spectral features were significantly altered in PM patients compared to healthy ones' spectra.The results indicate that the FTIR spectroscope may be used as a technique helpful in PM diagnostics. The study also presents preliminary results from the first prospective clinical validation study.