Chemical Composition Information Research Articles

Insights into a Low-Rank Naomaohu Coal Structural Information by Multistage Fractions Coupled with LIAD-VUVPI-TOFMS.

In-depth insights into the chemical composition and structural information of coal are an effective way to improve the efficiency of coal utilization. Laser-induced acoustic desorption coupling with vacuum ultraviolet photoionization time-of-flight mass spectrometry (LIAD-VUVPI-TOFMS) was applied to structural characterization of cyclohexane extracts of low-rank Naomaohu coal. The characterization of four types (12 model compounds) of mixed coal model compounds (three compounds per category)—saturated hydrocarbons, substitute aromatic hydrocarbons, aromatic hydrocarbons, and aromatic heteroatom rings—demonstrated that the approach can provide intact molecular weight information. The cyclohexanone extract (ECYC) was obtained by microwave-assisted extraction and separated into four group components (F1–4) by column chromatography to achieve component classification and simplify analysis. The molecular weight and structure were obtained by LIAD-VUVPI-TOFMS and synchronous fluorescence spectroscopy, combined with microwave-assisted extraction and column chromatography to separate product characteristics. Chemical components of a total of 248 species were observed, of which 46 are derived from aliphatic hydrocarbons embedded in the coal skeleton structure, 132 species are derived from aromatic hydrocarbons embedded in the coal skeleton structure, 61 are derived from possible coal skeleton units (compounds have obvious stacking and bonding effects), and 9 could not be determined (aromatic hydrocarbons or a possible coal skeleton structure unit).

Combined Raman and Turbidity Probe for Real-Time Analysis of Variable Turbidity Streams.

Real-time and in situ process monitoring is a powerful tool that can empower operators of hazardous processes to better understand and control their chemical systems without increased risk to themselves. However, the application of monitoring techniques to complex chemical processes can face challenges. An example of this is the application of optical spectroscopy, otherwise capable of providing detailed chemical composition information, to processes exhibiting variable turbidity. Here, details on a novel combined Raman spectroscopy and turbidimetry probe are discussed, which advances current technology to enable flexible and robust in situ monitoring of a flowing process stream. Furthermore, the analytical approach to accurately account for both Raman signal and turbidity while quantifying chemical targets is detailed. This new approach allows for accurate analysis without requiring assumptions of stable process chemistry, which may be unlikely in applications such as waste cleanup. Through leveraging Raman and turbidity data simultaneously collected from the combined probe within chemometric models, accurate quantification of multiple chemical targets can be achieved under conditions of variable concentrations and turbidity.

Three-dimensional nano-coherent diffraction imaging technology based on high order harmonic X-ray sources

Coherent diffractive imaging (CDI) using ultra-short wavelength light source has become an three-dimensional(3D) nanoimaging technique. In CDI, a target sample is first illuminated by a coherent EUV and soft X-ray light, then the diffraction pattern is recorded by using a charge coupled device (CCD), and finally the image of the sample is obtained based on the pattern by using a phase retrieval algorithm. Of the many currently available coherent EUV and soft X-ray light sources, the high-order harmonic generation (HHG) is the simplest in structure, the lowest in cost, and most compact in size. Therefore, it has become the most promising light source for CDI. Through years of development, HHG based CDI technique(HHG-CDI) has become an outstanding 3D nano-imaging technique with the advantages of no aberration, no damage, and no contact either, and it also possesses the extra-capabilities of probing the dynamics, chemical composition and quantum information in various semiconductor and quantum devices. We believe that the HHG-CDI will soon become a generic nano-imaging tool that can complement or even replace the matured nanoimaging techniques, such as atomic force, near field, X-ray, electron, or scanning tunneling microscopes.

Molecular mechanism of Si-Miao-Yong-An decoction in the treatment of diabetic foot microcirculation and network pharmacology information analysis results

OBJECTIVE: This study aims to explore the effect and mechanism of Si-Miao-Yong-An decoction (SMYAD) on diabetic foot by simulating the microenvironment of diabetic foot in vitro, and further verify these results using bioinformatics analysis technology, in order to provide a basis for the treatment of diabetic foot with traditional Chinese medicine. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured under hypoxia to simulate the microcirculation of diabetic foot. Then, these were administered with SMYAD for intervention. Afterward, the cell viability was detected by MTT assay, the apoptosis was detected by flow cytometry, and the STAT3 signaling pathway and Bcl-2 and Bax protein expression were detected by Western blot. Next, TCMSP was used to determine the chemical composition and target gene information of the SMYAD, and the GeneCards database was used to search for the disease-related target gene information of diabetic foot. Furthermore, the Venny 2.1 online software was used to screen and obtain the drug–disease common target genes for the SMYAD and diabetic foot. The common target genes were entered into the STRING database for retrieval, in order to construct the network diagram for protein-related action, and the R software was used to analyze the pathway enrichment, in order to explore the mechanism of the SMYAD in the treatment of diabetic foot microcirculation. RESULTS: Compared with the control group, the SMYAD increased the activity of HUVECs cultured in the hypoxia state but decreased the apoptosis rate. Furthermore, the protein expression of p-STAT3 and Bcl-2 increased, and the protein expression of Bax decreased (P < 0.05). A total of 235 drug-related target genes were found by screening, and 4553 target genes related to diabetic foot were obtained. The Venny software analysis revealed that there were 171 drug–disease interaction target genes. The STRING database and the GO and KEGG functional enrichment analysis revealed that STAT3, AKT, MAPK, and other proteins were involved, and that these may be correlated to the mechanism of the SMYAD in the treatment of diabetic foot microcirculation. CONCLUSION: SMYAD can affect the expression of Bcl-2 and Bax genes by regulating the activity of the STAT3 signaling pathway, playing a role in the treatment of diabetic foot.

Impact of Tetrabutylammonium on the Oxidation of Bromide by Ozone.

The reaction of ozone with sea-salt derived bromide is relevant for marine boundary layer atmospheric chemistry. The oxidation of bromide by ozone is enhanced at aqueous interfaces. Ocean surface water and sea spray aerosol are enriched in organic compounds, which may also have a significant effect on this reaction at the interface. Here, we assess the surface propensity of cationic tetrabutylammonium at the aqueous liquid–vapor interface by liquid microjet X-ray photoelectron spectroscopy (XPS) and the effect of this surfactant on ozone uptake to aqueous bromide solutions. The results clearly indicate that the positively charged nitrogen group in tetrabutylammonium (TBA), along with its surface activity, leads to an enhanced interfacial concentration of both bromide and the bromide ozonide reaction intermediate. In parallel, off-line kinetic experiments for the same system demonstrate a strongly enhanced ozone loss rate in the presence of TBA, which is attributed to an enhanced surface reaction rate. We used liquid jet XPS to obtain detailed chemical composition information from the aqueous-solution–vapor interface of mixed aqueous solutions containing bromide or bromide and chloride with and without TBA surfactant. Core level spectra of Br 3d, C 1s, Cl 2p, N 1s, and O 1s were used for this comparison. A model was developed to account for the attenuation of photoelectrons by the carbon-rich layer established by the TBA surfactant. We observed that the interfacial density of bromide is increased by an order of magnitude in solutions with TBA. The salting-out of TBA in the presence of 0.55 M sodium chloride is apparent. The increased interfacial bromide density can be rationalized by the association constants for bromide and chloride to form ion-pairs with TBA. Still, the interfacial reactivity is not increasing simply proportionally with the increasing interfacial bromide concentration in response to the presence of TBA. The steady state concentration of the bromide ozonide intermediate increases by a smaller degree, and the lifetime of the intermediate is 1 order of magnitude longer in the presence of TBA. Thus, the influence of cationic surfactants on the reactivity of bromide depends on the details of the complex environment at the interface.

In Situ Multimodal Optical Imaging Platforms to Study Battery Reactions

Increasingly complex and heterogeneous chemical reactions on the battery and catalytic electrode surfaces require the characterization methods to provide a complete picture of molecular interactions across the interface in situ. For example, the biggest challenge in accelerating the Li metal batteries towards higher energy density is the lack of fundamental understanding of interfacial chemical reaction on the electrode surface. During the initial lithiation cycles, a solid electrolyte interphase (SEI) forms on the electrode surface due to the electrochemical instability of the electrolyte. Inhomogeneity in reaction activity/deposition rate, chemical compositions, and ionic and electrical conductivity on the battery electrode will cause the non-uniform Li-ion diffusion, and lead to inhomogeneous nucleation and dendrite formation. The traditional imaging and measurement techniques have experienced challenges to characterize these complicated interfacial chemical reactions. For example, most of the methods only provide rich information at a certain time point in the dynamic process or measure an average result over a large area during the reaction. On the other hand, these interfacial reactions are highly dynamic and spatially varied, and the signals at different time points or different locations could be totally different.We have developed a multimodal optical imaging platform to image the battery electrode reaction dynamics across the interfaces throughout the entire reaction process. The platform includes a 3D optical microscope, surface plasmon microscope, optical reflection microscope, and Raman spectrometry. The 3D optical microscope allows us to image the morphology changes during the battery reaction dynamics. The Zn deposition process on 3D Zn-Mn alloy electrode has been studied, and the 3D morphology and the Zn nucleation have been imaged in situ. We have also used the surface plasmon microscope, optical reflection microscope, and Raman spectrometry to study the SEI formation on Li metal electrodes. The platform provides us important interfacial chemical information, including SEI formation and chemical compositions: 1) The plasmonic imaging technique provides us information on localized SEI thickness and localized charging status during the reactions; 2) optical reflection microscope allow us to study the SEI and Li nucleation dynamics; and 3) Raman spectrometry provide us chemical composition information. The integration of all the information obtained from this multimodal imaging platform will allow us fundamentally understand SEI formation and electrochemical reaction on the anode electrode.

(Invited) Developing in Situ Optical Imaging Techniques to Understand Battery Solid Electrolyte Interface Formation

Developing in situ Optical Imaging Techniques to Understand Battery Solid Electrolyte Interface FormationXiaonan Shan. Xu Yang, Guangxia Feng, Yaping Shi, ECE, University of Houston Increasingly complex and heterogeneous chemical reactions on the battery and catalytic electrode surfaces require the characterization methods to provide a complete picture of molecular interactions across the interface in situ. For example, the biggest challenge in accelerating the Li metal batteries towards higher energy density is the lack of fundamental understanding of interfacial chemical reaction on the electrode surface. During the initial lithiation cycles, a solid electrolyte interphase (SEI) forms on the electrode surface due to the electrochemical instability of the electrolyte. Inhomogeneity in reaction activity/deposition rate, chemical compositions, and ionic and electrical conductivity on the battery electrode will cause the non-uniform Li-ion diffusion, and lead to inhomogeneous nucleation and dendrite formation. The traditional imaging and measurement techniques have experienced challenges to characterize these complicated interfacial chemical reactions. For example, most of the methods only provide rich information at a certain time point in the dynamic process, or measure an average result over a large area during the reaction. On the other hand, these interfacial reactions are highly dynamic and spatially varied, and the signals at different time points or different locations could be totally different. We have developed a multimodal optical imaging platforms to image the battery electrode reaction dynamics across the interfaces throughout the entire reaction process. The platform includes surface plasmon microscope, optical reflection microscope, and Raman spectrometry. The platform provides us important interfacial chemical information including SEI formation and chemical compositions: 1) The plasmonic imaging technique provide us information of localized SEI thickness and localized charging status during the reactions; 2) optical reflection microscope allow us to study the SEI and Li nucleation dynamics; and 3) Raman spectrometry provide us chemical composition information. The integration of all the information obtained from this multimodal imaging platform will allow us fundamentally understand SEI formation and electrochemical reaction on the anode electrode.

Chromatographic Fingerprinting Based on Column Switching Technology for Quality Evaluation of Tianmeng Oral Liquid.

Separation power was limited when the conventional high-performance liquid chromatography (HPLC) fingerprinting method based on a single column was used to analyze very complex traditional Chinese medicine (TCM) preparations. In this research, a novel HPLC fingerprinting method based on column switching technology by using a single pump was established for evaluating the quality of Tianmeng oral liquid (TMOL). Twelve batches of TMOL samples were used for constructing HPLC fingerprints. Compared with the 16 common peaks in fingerprinting with a single column, 25 common peaks were achieved with two columns connected through a six-way valve. The similarity analysis combined with bootstrap method was applied to determine the similarity threshold, which was 0.992 to distinguish expired samples and unexpired samples. Principal component analysis (PCA) and hierarchical clustering analysis (HCA) were also applied to classify the TMOL samples, and results revealed that expired and unexpired samples are classified into two categories. The HPLC fingerprinting based on column switching technology with better separation power and higher peak capacity could characterize chemical composition information more comprehensively, providing an effective and alternative method to control and evaluate the quality of TMOL, which would offer a valuable reference for other TCM preparations.

Wood Chemical Compositions of Raru Species Originating from Central Tapanuli, North Sumatra, Indonesia: Effect of Differences in Wood Species and Log Positions

Raru is a lesser-known plant species originating from North Sumatra, Indonesia. Information on the characteristics is still limited, especially its chemical component. Therefore, this study aims to examine the chemical composition information of Cotylelobium lanceolatum, Cotylelobium melanoxylon, and Vatica pauciflora woods based on their axial log positions (bottom, middle, and top). The wood chemical analysis was performed in terms of the Indonesian National Standard (SNI) method. Furthermore, the analysis measured holocellulose, α-cellulose, hemicellulose, lignin content, alcohol benzene extractive content, the extractive substance in hot and water, and solubility in NaOH 1%. The results indicated that the species and their log axial positions affected different chemical components, which included α-cellulose, hemicellulose, and lignin of C. lanceolatum amounting to 41.88%, 19.39%, and 28.68% respectively. Meanwhile, for C. Melanoxylon, they were 42.01%, 21.11%, and 24.76% respectively; and for V. pauciflora wood, they were 42.95%, 23.24%, and 30.11% respectively. The average values of the extractive contents including the solubility in 1: 2 ethanol benzene, NaOH, and hot water for C. lanceolatum, C. melanoxylon, and V. pauciflora wood were (10.58%, 27.62%, 8.13%), (14.54%, 28.22%, 7.82%), and (10.95%, 28.60%, 7.57%) respectively. The wood species had a significant effect on chemical components including lignin, cellulose and hemicellulose, and extractive solubility in cold water. Furthermore, the axial log position had a significant effect on all the parameters of the chemical composition of the wood being tested.

Application of approach for development of hptlc identification and quantification methods for determination of phenolic compounds and terpenoids of several Thymus L. species

The aim of this work was to improve the approaches for standardization of Thymus L. species by development of HPTLC identification of phenolic compounds (flavonoids and phenylpropanoids) and terpenoids (essential oils and triterpenoids) and quantitative determination of rosmarinic acid and flavonoids for six Thymus L. species of Ukraine flora, as well as determination of chromatographic profiles of Thymus L. species’ extracts obtained using different extraction methods.
 Materials and methods. Objects were: samples of dry herb of Th.serpyllum, Th.vulgaris, Th.Marschallianus, Th.Pallasianus, Th.calcareus, and Th.moldavicus of Ukraine origin collected in 2019-2021 years or acquired commercially on Ukraine market. Instruments: CAMAG HPTLC Herbal System, visionCats 2.5. The analytical grade reagents were used. Reference substances were purchased from Extrasynthese, Sigma Aldrich. Chromatography was performed on HPTLC plates Si 60 F254, Merck according to the developed methods.
 Results. A new approach for quality control of different Thymus L. species of Ukraine flora included the development of HPTLC methods for identification of main groups of bioactive substances of these species, such as flavonoids and phenylpropanoids, essential oils, triterpenoids; development of quantification method of rosmarinic acid and assay of total flavonoids, expressed as luteolin-7-O-glucoside. The characteristic HPTLC fingerprints of six Thymus L. species in three mobile phases of different polarities that cover a wide range of bioactive substances were established. The content of rosmarinic acid in different Thymus L. species samples was in the range of 0,11-0,72 %: Th.moldavicus – 0,11 %; Th.Marschallianus – 0,19-0,27 %; Th.serpyllum – 0,38 %; Th.vulgaris – 0,51 %; Th.calcareus – 0,56 %; T.Pallasianus – 0,72 %. The total flavonoids content, expressed as luteolin-7-O-glucoside, was in the range of 0,8-2,72 %: Th.moldavicus – 0,8 %; Th.serpyllum – 0,87 %; Th.vulgaris – 1,06 %; Th.Pallasianus – 1,28 %; Th.Marschallianus – 1,89 %; Th.calcareus – 2,72 %.
 Conclusions. The proposed scientific approach for quality evaluation of Thymus L. species using HPTLC allows to determine comprehensive information of chemical composition and content of active substances of multiple samples in parallel, in a cost and time-efficient manner

Cloud condensation nuclei characteristics at the Southern Great Plains site: role of particle size distribution and aerosol hygroscopicity

The activation ability of aerosols as cloud condensation nuclei (CCN) is crucial in climate and hydrological cycle studies, but their properties are not well known. We investigated the long-term measurements of atmospheric aerosol properties, CCN concentrations (NCCN) at supersaturation (SS = 0.1%–1.0%), and hygroscopicity at the Department of Energy’s Southern Great Plains (SGP) site to illustrate the dependence of NCCN on aerosol properties and transport pathways. Cluster analysis was applied to the back trajectories of air masses to investigate their respective source regions. The results showed that aged biomass burning aerosols from Central America were characterized by higher accumulation mode particles (Naccu; median value 805 cm−3) and relatively high aerosol hygroscopicity (κ; median value ∼0.25) values that result in the higher CCN activation and relatively high NCCN (median value 258–1578 cm−3 at a SS of 0.1%–1.0%). Aerosols from the Gulf of Mexico were characterized by higher Naccu (∼35%), and NCCN (230–1721 cm−3 at a SS of 0.1%–1.0%) with the lowest κ (∼0.17). In contrast, relatively high nucleation mode particles (Nnucl; ∼20%) and low NCCN (128–1553 cm−3 at a SS of 0.1%–1.0%) with higher κ (∼0.30) values were observed on the aerosols associated with a westerly wind. The results indicate particle size as the most critical factor influencing the ability of aerosols to activate, whereas the effect of chemical composition was secondary. Our CCN closure analysis suggests that chemical composition and mixing state information are more crucial at lower SS, whereas at higher SS, most particles become activated regardless of their chemical composition and size. This study affirms that soluble organic fraction information is required at higher SS for better NCCN prediction, but both the soluble organics fraction and mixing state are vital to reduce the NCCN prediction uncertainty at lower SS.

One-Step Preparation of Robust Superhydrophobic Foam for Oil/Water Separation by Pulse Electrodeposition.

Frequent leakage and pollution of oily wastewater seriously affect the world's ecosystem safety and economic development, which prompts us to urgently develop a highly effective, low-cost, wear-resistant, chemically stable, and environmentally friendly new functional material for oil/water separation. In this paper, a robust superhydrophobic material was successfully electrodeposited on the porous copper foam substrates in myristic acid (CH3(CH2)12COOH) and lanthanum chloride (LaCl3·6H2O) electrodeposition solution under a continuous pumping circulation and rotation condition. Moreover, SEM, EDS, XRD, FTIR, and XPS technologies were utilized to characterize the surface morphology and chemical composition information. The superhydrophobic property was evaluated by optical contact angle instrument and high-speed camera. It turned out that the micro/nanostructures were mainly composed of lanthanum myristate, and static CA of superhydrophobic copper foam (SCF) was up to 165.2° with SA ≈ 2°. Besides, the SCF exhibited a better performance with good anticorrosion, excellent chemical stability, and outstanding mechanical stability. Furthermore, the SCF can achieve up to 98.6% oil/water separation efficiency. More importantly, by employing this novel processing method, it can effectively save time and provide a promising potential way to make denser and thicker foams for continuous oil/water separation and may be easily applied to other conductive metal matrix materials.

In Situ Identification and Spatial Mapping of Microplastic Standards in Paramecia by Secondary-Ion Mass Spectrometry Imaging.

Microplastics (MPs) are universally present in the ecosystem and pose great threats to the environment and living organisms. Research studies have shown that small MPs (<50 μm in diameter) are especially toxic and account for more than half of all MPs collected in the Atlantic Ocean. Nevertheless, current methods for the detection and analysis of MPs are incapable of achieving rapid and in situ analysis of small MPs in the biota to ultimately enable the study of their biological effects. In this work, we report a method that allows rapid in situ identification and spatial mapping of small MPs directly from paramecia with high accuracy by acquiring chemical composition information using secondary-ion mass spectrometry (SIMS) imaging. Specifically, six types of common MPs (polymethyl methacrylate, polyvinyl chloride, polypropylene, polyethylene terephthalate, polyglycidyl methacrylate, and polyamide 6) with a diameter of 1-50 μm were simultaneously imaged with high chemical specificity at a spatial resolution of 700 nm. In situ spatial mapping of a group of MPs ingested by paramecia was performed using SIMS fragments specific to the plastic composition with no sample pretreatment, revealing the aggregation of MPs in paramecia after ingestion. Compared with existing methods, one additional advantage of the developed method is that the MPs and the organism can be analyzed in the same experimental workflow to record their fingerprint spectra, acquiring biochemical information to evaluate MP fate, toxicity, and the MP-biota interaction.

Specialized products for dietary correction of the diet of patients with non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is a widespread disorder associated with a number of metabolic disorders. Lifestyle modification, including diet and physical activity are currently a first-line treatment for the disease. However, there is lack of specialized products (SP) with modified carbohydrate and fat composition, containing biologically active ingredients with proven physiological effects on the liver for this disorder. The aim of the paper is to summarize present knowledge on the biologically active ingredients with proven hepatoprotective effect and to describe the process of the development of two specialized products for clinical use in patients with NASH. Material and methods. Food ingredients containing soy and milk proteins, soluble dietary fiber, mono- and polyunsaturated fatty acids, vitamins, minerals, soy lecithin, L-carnitine, coenzyme Q10, α-lipoic acid, betaine, flavoring and aromatic additives were used in the development of SP formulations. The mass fraction of moisture in the SP was determined by the thermo-gravimetric method on a humidity analyzer, and the water activity was determined by measuring the dew point. The nutritional and energy value of the SP was calculated using data from chemical composition tables and information from manufacturers of food ingredients. Results and discussion. Taking into account the requirements for dietary therapy, the ingredient composition was scientifically justified and the formulations of two SP with a balanced amino acid composition were developed by using a combination of milk whey proteins, casein and soy protein isolate. The fat component included microencapsulated rapeseed oil, that is a source of mono- and polyunsaturated fatty acids (PUFAs) with the addition of ω-3 PUFAs. The carbohydrate composition was modified by eliminating mono- and disaccharides, traditionally used in sweet drinks, and adding maltodextrin in combination with sweeteners (polyols and natural sweeteners). Polydextrose, citrus pectin, inulin, and hydrolyzed guar gum are used as soluble dietary fibers. The SP included essential micronutrients (vitamins, mineral substances) and bioactive substances that have a proven physiological effect (coenzyme Q10, α-lipoic acid, L-carnitine, betaine hydrochloride, phospholipids). Technical documentation was developed and a pilot batch of SP-1 was developed for inclusion in the complex treatment of patients with NASH. Conclusion. The formulations and technology of SP (SP-1, SP-2) for therapeutic nutrition with a given chemical composition, designed to optimize the diet therapy of patients with NASH, have been developed. SP are sources of animal and vegetable proteins, soluble dietary fiber, mono- and polyunsaturated fatty acids, including ω-3 family, vitamins, minerals and trace elements, as well as bioactive substances with antioxidant, hepatoprotective and hypolipidemic effect. The technical documentation was developed and approved, according to which a pilot batch of SP-1 was produced to assess its effectiveness as a part of complex therapy of patients with NASH.

PyXtal: A Python library for crystal structure generation and symmetry analysis

We present PyXtal, a new package based on the Python programming language, used to generate structures with specific symmetry and chemical compositions for both atomic and molecular systems. This software provides support for various systems described by point, rod, layer, and space group symmetries. With only the inputs of chemical composition and symmetry group information, PyXtal can automatically find a suitable combination of Wyckoff positions with a step-wise merging scheme. Further, when the molecular geometry is given, PyXtal can generate different dimensional organic crystals with molecules occupying both general and special Wyckoff positions. Optionally, PyXtal also accepts user-defined parameters (e.g., cell parameters, minimum distances and Wyckoff positions). In general, PyXtal serves three purposes: (1) to generate custom structures, (2) to modulate the structure by symmetry relations, (3) to interface the existing structure prediction codes that require the generation of random symmetric structures. In addition, we provide several utilities that facilitate the analysis of structures, including symmetry analysis, geometry optimization, and simulations of powder X-ray diffraction (XRD). Full documentation of PyXtal is available at https://pyxtal.readthedocs.io. Program summaryProgram Title: PyXtalCPC Library link to program files:https://doi.org/10.17632/wfyxyhjzwx.1Licensing provisions: MIT [1]Programming language: Python 3Nature of problem: Knowledge of structure at the atomic level is the key to understanding materials’ properties. Typically, the structure of a material can be determined either from experiment (such as X-ray diffraction, spectroscopy, microscopy) or from theory (e.g., enhanced sampling, structure prediction). In many cases, the structure needs to be solved iteratively by generating a number of trial structure models satisfying some constraints (e.g., chemical composition, symmetry, and unit cell parameters). Therefore, it is desirable to have a computational code that is able to generate such trial structures in an automated manner.Solution method: The PyXtal package is able to generate many possible random structures for both atomic and molecular systems with all possible symmetries. To generate the trial structure, the algorithm can either start with picking the symmetry sites randomly from high to low multiplicities, or use sites that are predefined by the user. For molecules, the algorithm can automatically detect the molecules’ symmetry and place them into special Wyckoff positions while satisfying their compatible site symmetry. With the support of symmetry operations for point, rod, layer and space groups, PyXtal is suitable for the computational modeling of systems from zero, one, two, and three dimensional bulk crystals.

Metabolite Profiling and Comparative Analysis of Secondary Metabolites in Chinese Cabbage, Radish, and Hybrid xBrassicoraphanus.

We profiled and quantified primary and secondary metabolites in the leaves and roots of xBrassicoraphanus (Baemuchae), Brassica campestris ssp. pekinensis (Chinese cabbage), and Raphanus sativus (radish). We obtained 72 metabolites from leaves and 68 metabolites from both leaves and roots of xBrassicoraphanus, Chinese cabbage, and radish. The metabolic profiles in this study revealed intermediate-level production of most metabolites from different parts of Baemuchae compared with that from different parts of Chinese cabbage and radishes. This was supported by the results of principal component analyses for the detected metabolites, which indicated that the Baemuchae group was located between the Chinese cabbage and radish groups. In particular, several amino acids (phenylalanine, tryptophan, and methionine) played the main role in phenylpropanoid and glucosinolate biosynthesis and were positively correlated with phenolic compounds, indolic glucosinolates, and aliphatic glucosinolates, respectively, in different parts. Furthermore, analysis of different species revealed the presence of 10 different glucosinolates, 10 phenolics, and 7 carotenoids, and their levels varied in the roots and leaves of the studied species. Among the leaves of the three species, Chinese cabbage had the highest total glucosinolate level, which was 3.14 times higher than the lowest level observed in radish. Baemuchae had the highest total phenolic compound level, which was 2.87 times higher than the lowest level found in Chinese cabbage, and radish had the highest carotenoid level, which was 12.41 times higher than the lowest one observed in Chinese cabbage. In the roots of Baemuchae, Chinese cabbage, and radish, glucosinolate levels did not vary significantly. Chinese cabbage contained the highest total phenolic compound level, which was 2.38 times higher than the lowest level found in radish, and the highest total carotenoid level, which was 2.49 times higher than the lowest level observed in Baemuchae. This metabolomic study provided chemical composition information that can be applied to future breeding strategies and comprehensively described the relationship among metabolites detected in the three plant species.

Real-time monitoring of calcium sulfate scale removal from RO desalination membranes using Raman spectroscopy

Chemical characterization of scaling and removal processes was performed in real time via Raman spectroscopy in a bench-scale reverse osmosis (RO) system. A custom RO cross-flow cell was integrated with a Raman microscope objective, allowing for analysis of localized membrane scaling and scale removal. Permeate flux was also measured to provide a real-time metric for comparison. A commercial flat sheet, thin-film composite reverse osmosis (TFC RO) membrane was scaled using a calcium sulfate (CaSO4·H2O) feed solution. Upon CaSO4 scale detection, the feed was switched to DI water, which served as a cleaning agent to remove the CaSO4 scale from the membrane. In addition to the real-time local (Raman) and global (permeate flux) measurements, membrane samples were characterized post-mortem using Raman spectroscopy, gravimetric analysis and scanning electron microscopy to provide important scaling and scale removal metrics. Results from real-time measurements indicated that changes in Raman intensity were a more sensitive indicator of local scale removal than changes in permeate flux, a standard cleaning performance metric; these findings were corroborated by the post-mortem analyses. Overall, the membrane cleaning experiments showed that Raman spectroscopy provided crucial real-time chemical composition and spatial distribution information, which can inform more effective antiscaling and cleaning strategies.

Improvement of CrMoN/SiNx coatings on mechanical and high temperature Tribological properties through biomimetic laminated structure design

CrMoN/SiNx multilayered coatings were fabricated by controlling the shutter-open time of two sputtering guns in a radio frequency magnetron sputtering system. Employing the structure of nacreous shells from nature, nano-crystalline and amorphous monolayers were periodically stacked. CrMoN/SiNx thin films with different bi-layer periods were deposited on Si-wafer and Inconel-718 substrates. The phases of the coatings were examined using a grazing incidence X-ray diffraction (XRD) technique. Information of chemical composition was obtained by field emission electron probe micro-analyzer (FE-EPMA). The confirmation of multilayer structure was observed by transmission electron microscope (TEM). The wear tracks were revealed by scanning electron microscope (SEM). Mechanical and high-temperature tribological properties were evaluated using a nano-indenter and a high-temperature tribometer, respectively.Grain refinement phenomenon was verified using XRD peak broadening at high angles, indicating inhibition in the column structure and the formation of an amorphous phase. CrMoN/SiNx exhibited higher high-temperature wear resistance for a specific bi-layer period, which was attributed to the multilayer strengthening mechanism. Multilayered structure provided tremendous benefit to COF improvement, which was reduced by 50% of the value of CrMoN. Simultaneously, the toughening effect of the biomimetic structure design improved the wear resistance ability of the coating. Especially, the slight amount of SiNx unpredictably enhanced the wearing properties of the system, which is in consistent with the role of chitin in nacre. Moreover, an optimal bi-layer period was identified, resulting in optimal mechanical properties that were consistent with the high-temperature tribological properties. Furthermore, the wear tracks on the specimens were analyzed through field-emission scanning electron microscopy, which support the wearing behavior alteration. Finally, a CrMoN/SiNx multilayer coating with optimal high-temperature characteristics was demonstrated in this study.

A combined approach of atom probe tomography and unsupervised machine learning to understand phase transformation in (AlxGa1−x)2O3

In this paper, we investigated the evolution of microstructural chemistry of metal organic chemical vapor deposition grown (010) (AlxGa1−x)2O3 films with varying Al contents, x = 0.10–1.0, using atom probe tomography (APT). At a low Al content (x ≤ 0.25), the films are homogeneous, where layer inhomogeneity appears at a high Al content (x &amp;gt; 0.25). Further increasing the Al content up to x ≥ 0.60 results in a homogeneous (AlxGa1−x)2O3 layer. This change in microstructural features was linked to the phase transformation of (AlxGa1−x)2O3 using a manifold learning approach to capture the governing features hidden in the data dimensionality. Combining APT to unsupervised machine learning enables APT to be an independent material characterization tool to investigate the microstructure, chemical composition, and phase related information.

Dynamical Mechanical and Thermal Analyses of Biodegradable Raw Materials for Additive Manufacturing.

In order to find new ways to ensure sustainable development on a global level, it is essential to combine current top technologies, such as additive manufacturing, with the economic, ecological, and social fields. One objective of this paper refers to wire manufacture such as Arboblend V2 Nature, Arbofill Fichte, and Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” (BDP—Biodegradable Plastic) in order to replace the plastic materials. After wire manufacture by extrusion, the diameter accuracy was analyzed compared with the Fiber Wood wire using SEM analyses and also EDAX—Energy Dispersive X-ray Analysis and DSC—Differential Scanning Calorimetry analyses were done in order to identify their elemental composition and the phase transitions suffered by the materials during heating. Using the samples obtained through the Fused Deposition Modeling (FDM) method, both crystalline phases and chemical composition information (XRD analysis) were identified, as well was determined the visco-elastic behavior Dynamic Mechanical Analysis (DMA), for the reinforced material and Fiber Wood. The extruded wires have allowed size for the printing equipment, around 1.75 mm with tolerance of ± 0.05 mm. The wire material diagrams, Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” and Fiber Wood following the calorimetric analysis, presented peaks corresponding to material crystallization, while Arbofill Fichte revealed only the melting temperature. The storage module was almost double in case of Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” compared with Fiber Wood and materials’ melting temperatures were confirmed by the analyses carried out.