Chemical Character Research Articles

Intercalation-assisted Exfoliation Strategy for Two-dimensional Materials Preparation

Controlled large-quantity synthesis of two-dimensional materials is vital for the research on their physical and chemical characters and potential applications. Utilizing structural features of layered compounds, intercalation of molecules or ions can be applied to the acceleration of liquid-phase exfoliation. In this review, we aim at recent progress on synthesis of two-dimensional materials via intercalation-assisted exfoliation strategy. Works on wet chemical intercalation and electrochemical intercalation, together with product exfoliation afterwards, are summarized. Furthermore, the features and advantages of intercalation-assisted exfoliation strategy for two-dimensional materials synthesis are discussed.

The True Amphipathic Nature of Graphene Flakes: A Versatile 2D Stabilizer.

The fundamental colloidal properties of pristine graphene flakes remain incompletely understood, with conflicting reports about their chemical character, hindering potential applications that could exploit the extraordinary electronic, thermal, and mechanical properties of graphene. Here, the true amphipathic nature of pristine graphene flakes is demonstrated through wet-chemistry testing, optical microscopy, electron microscopy, and density functional theory, molecular dynamics, and Monte Carlo calculations, and it is shown how this fact paves the way for the formation of ultrastable water/oil emulsions. In contrast to commonly used graphene oxide flakes, pristine graphene flakes possess well-defined hydrophobic and hydrophilic regions: the basal plane and edges, respectively, the interplay of which allows small flakes to be utilized as stabilizers with an amphipathic strength that depends on the edge-to-surface ratio. The interactions between flakes can be also controlled by varying the oil-to-water ratio. In addition, it is predicted that graphene flakes can be efficiently used as a new-generation stabilizer that is active under high pressure, high temperature, and in saline solutions, greatly enhancing the efficiency and functionality of applications based on thismaterial.

Soil organic matter content and its aliphatic character define the hydrophobicity of biocrusts in different successional stages

AbstractIn humid areas, biocrusts cover topsoils of inland dunes and influence soil characteristics, which, in turn, may affect the hydrophobicity of soils. The hydrophobicity of topsoils typically increases with increasing organic matter content. In addition, the soil organic matter quality, for example, described by the ratio of its hydrophilic and hydrophobic functional groups, also influences hydrophobicity. Because biocrust development goes along with an increase in the organic matter content and a shift in microbial community composition, the chemical character of soil organic matter likely changes over time, which, in turn, affects the hydrophobicity of the crusts. We hypothesize that the hydrophobicity of biocrusts increases during succession because of increasing amounts and aliphatic character of organic matter. We compared organic matter contents and Fourier‐transform infrared spectra of cyanobacterial biocrusts and moss‐dominated biocrusts at two European inland dunes. The organic carbon content as well as the hydrophobicity increased during crust development at both sites. Older moss‐dominated biocrusts showed the highest hydrophobicity and the highest organic carbon content. Moreover, at one study site, the hydrophobicity of the biocrusts did increase with decreasing ratio between hydrophilic and hydrophobic (i.e., aliphatic) moieties of soil organic matter. At the second study site, this effect was only visible for the moss‐dominated biocrust. We conclude that biocrust development and organic matter accumulation go ahead with changes in the organic matter composition and induce increased hydrophobicity with a strong impact on water redistribution in inland dune ecosystems. This knowledge will help to improve nature protection strategies in rare ecosystems.

EFFECT OF FOLIAR SPRAY WITH AQUEOUS EXTRACT OF DATE PALM POLLEN GRAINS AND LITHOVIT ON COMMON BEAN PLANTS UNDER DIFFERENT IRRIGATION LEVELS

Two field experiments were carried out during two successive seasons of 2017 and 2018 at the Experimental Farm of Kaha Station, Qalubia Governorate, Egypt. The study investigated the effect of three irrigation levels (50%, 75% and 100%) from crop evapotraspiration (ETc) and five foliar spraytreatments by aqueous extract of date palm pollen grains at 1, 3 and 5 g/l, lithovit at 1 g/l and tap water (control) on common bean plants c.v.Nebraska. The effect of treatments on growth, seed yield, chemical characters as well as water use efficiency were studied. The recorded results illustrated that the plants sprayed by date palm pollen grains extract at 5 g/l and irrigated by 100% (968.72 m3 water/fad.) or 75% (726.54 m3 water/fad.) of irrigation water, gave the highest values of all vegetative growthparameters. On the other hand, the plants sprayed with date palm pollen grains extract at 1, 3 or 5 g/l followed by lithovit at 1 g/l, respectively and irrigated by 100% or 75% of irrigation water gave the highest value for each of number of pods/plant, weight of 1000 seeds and total dry seed yield ton/fad., compared to the control, i.e. water foliar spray treatment in both growing seasons. Water use efficiency (WUE) decreased when the amount of irrigation water increased to 100% ETc and the highest values were obtained from 50% treatment followed by 75% Etc. Moreover, the plants sprayed with date palm pollen grains extract at 5, 3 or 1 g/l, respectively,followed by lithovit at 1 g/L (nano-fertilizer) showed the highest values of WUE. Generally, it can recommend by spraying common bean plants by date palm pollen grains extract at (5, 3 or 1 g/l)respectively,followed by lithovit at 1 g/l (nano-fertilizer) with irrigation at level of 75% from ETc to obtain the highest seed yield with the best quality and the favorable water use efficiency at the same time saving 25% from water irrigation quantity.

Molecular Docking of Curcumin With Breast Cancer Cell Line Proteins

Background: Breast cancer is known as the most widely recognized dangerous tumors; therefore, the most common reason for mortality among all instances of harmful neoplastic illness in females. This is because the lack of specific signs and symptoms at the early stage and at the aggressive nature. Currently, breast cancer treatment such as chemotherapy, surgery and radiotherapy has not been effective.
 Objectives: In this study, Three-Dimensional (3D) structures of caspase 3, mucosal addressin cell adhesion molecule 1 (MADCAM1) and nuclear factor NF-kappa-B-p105 subunit (breast cancer cell line proteins) were created; and their binding interaction between proteins and curcumin through molecular docking approach were studied.
 Methods: The proteins were created using Swiss model and viewed by PyMol software. The physical and chemical characters of the proteins were analysed by Expasy’s ProtParam Proteomics server. Besides that, the secondary structures of the proteins were analysed by SOPMA (Self Optimized Prediction Method from Alignment) server. After that, they were evaluated by PROCHECK, ProQ, ERRAT, and Verify3D analysis. Lastly, the breast cancer cell line proteins were docked with curcumin using BSP-Slim server.
 Results: All the protein structures were good quality and within the acceptable range. The curcumin showed the binding energy with caspase 3, mucosal addressin cell adhesion molecule 1 and nuclear factor NF-kappa-B-p105 subunit at 4.140, 7.201 and 3.165 kcal/mol respectively.
 Conclusion: The nuclear factor NF-kappa-B-p105 subunit had the strongest bond with curcumin. Curcumin can be potential drug for breast cancer treatment. Therefore, it can further be investigated in laboratory experiments.

Formulation and Evaluation of Levocetirizine Dihydrochloride and Ambroxol Hydrochloride Lozenges

The present work aims to formulate and evaluate levocetirizine dihydrochloride and ambroxol hydrochloride hard candy lozenges to produce a slow-release of drugs for the management of cold and cough. The lozenges were prepared using sucrose, liquid glucose, hydroxyethylcellulose, and hydroxypropyl methylcellulose K4M by heating and congealing method. Sweetener with flavors was utilized to facade the bitter taste of the drug. The developed lozenges were exposed to various physical and chemical characters, and in vitro disintegration and dissolution. The developed formulations include hardness of 8 to 11 kg/cm², non-gritty, and agreeable mouthfeel. The optimized formula was examined for drug excipient interactions subjecting to Fourier transform infrared (FTIR) spectral analysis. Drug release for lozenges was highest in formulation FL8. The hard candy lozenges can present an attractive substitute formulation in allergic conditions.

Morphological and Chemical Traits as Quality Determinants of Common Thyme (Thymus vulgaris L.), on the Example of ‘Standard Winter’ Cultivar

Common thyme is regarded as one of the most important culinary plants. The purpose of the work was to determine the intraspecific variability of common thyme with respect to morphological and chemical characters including the content and composition of essential oil and phenolic compounds in the herb. The objects of the study were 12 clones, vegetatively multiplied from randomly selected individual plants of cultivar ‘Standard Winter’. The morphological observations and harvest of raw materials were carried out in the first year plants’ vegetation. The highest differences between clones were on fresh and dry weight of herb (CV = 0.38 and 0.36, respectively), width of leaves (CV = 0.21), and density of glandular trichomes on the abaxial surface of leaves (CV = 0.29). Examined clones were also differentiated as to the chemical features. Essential oil content (performed by hydrodestillation) and composition (by GC-MS and GC-FID) were determined and they ranged from 2.10 to 4.38 g × 100 g−1 DW. Here, thymol, γ-terpinen, and p-cymen were the dominant compounds. Clone no. 4 was distinctive as to the highest content of essential oil followed by the highest share of thymol (54.59%). The total content of phenolic acids and flavonoids (determined according to PPh 6th) also differed among clones (CV = 0.38 and 0.36, respectively). Using a validated HPLC-DAD method, the following compounds were identified: caffeic, rosmarinic, p-coumaric acids, luteolin 7-O-glucoside, naryngenin, and (−)-epicatechin. Here, rosmarinic acid followed by luteolin 7-O-glucoside were present in the highest amounts (611.47–2675.59 and 46.77–325.11 mg × 100 g−1 DW, respectively). The highest differences between clones were the contents of p-coumaric acid (CV = 0.59), luteolin 7-O-glucoside (CV = 0.50) and rosmarinic acid (CV = 0.40). Such a high range of variability can provide problems with raw material standardization. Nevertheless, it opens possibilities for breeders, whereas individual plants/clones may become valuable components for breeding.

Effect of Thinning Treatments on some Physical and Chemical Fruit Characters of Barhy and Magdool Date Palm Cultivars

Effect of Thinning Treatments on some Physical and Chemical Fruit Characters of Barhy and Magdool Date Palm Cultivars

Effect of Different Sources of Pollen Grains on Some Physical and Chemical Fruit Characters of Barhy Date Palm Cultivar

Effect of Different Sources of Pollen Grains on Some Physical and Chemical Fruit Characters of Barhy Date Palm Cultivar

IDM‐1: A Zeolite with Intersecting Medium and Extra‐Large Pores Built as an Expansion of Zeolite MFI

AbstractIDM‐1 is a new silica zeolite with an ordered and well‐defined framework constructed by alternating pentasil layers and interrupted layers, giving rise to an intersecting system of straight medium pores and undulating extra‐large lobed pores. This unique structure was solved by rotation electron diffraction and refined against synchrotron powder X‐ray diffraction data. Despite the presence of both Si(OSi)3(OH) and Si(OSi)2(OH)2 sites, this new zeolite presents high thermal stability, withstanding calcination even to 1000 °C. The location of defects at specific sites of the structure results in alternating hydrophobic SiO2 and hydrophilic SiO(2−x)(OH)2x intracrystalline regions. This peculiar combination of intersecting medium and extra‐large pores and alternating regions of different chemical character may provide this zeolite with unique catalytic properties.

IDM‐1: A Zeolite with Intersecting Medium and Extra‐Large Pores Built as an Expansion of Zeolite MFI

IDM-1 is a new silica zeolite with an ordered and well-defined framework constructed by alternating pentasil layers and interrupted layers, giving rise to an intersecting system of straight medium pores and undulating extra-large lobed pores. This unique structure was solved by rotation electron diffraction and refined against synchrotron powder X-ray diffraction data. Despite the presence of both Si(OSi)3 (OH) and Si(OSi)2 (OH)2 sites, this new zeolite presents high thermal stability, withstanding calcination even to 1000 °C. The location of defects at specific sites of the structure results in alternating hydrophobic SiO2 and hydrophilic SiO(2-x) (OH)2x intracrystalline regions. This peculiar combination of intersecting medium and extra-large pores and alternating regions of different chemical character may provide this zeolite with unique catalytic properties.

ASSESSMENT OF SURFACE WATER RESOURCES FOR IRRIGATION PURPOSES IN ASSIUT GOVERNORATE, UPPER EGYPT

Water from some sources may contain so much salt that it is unsuitable for irrigation because of potential danger to the soil or crops. Irrigation water quality can best be determined by chemical laboratory analysis. The main objectives of this study are to assess the surface water quality for irrigation, and to present solutions for managing and protecting these resources in Assiut area. To achieve that, thirty surface water samples were collected from River Nile and main irrigation canals. Chemical analysis was carried out and analyzed for major and trace elements according to the irrigation water guidelines of (FAO 1985), and (Rowe, et al. 1995), taking into account the spatial variations and the representation of the hydro chemical data. The results show that 97% of surface water samples lie within no restriction on use level and 3% is represent slight to moderate restoration on use according to TDS concentrations. 97 % of surface water samples belongs to (C2-S1) good water for irrigation all crops in all soils and 3 % belongs to (C3 -S1) good water for irrigation all crops in all soils under ordinary and specific condition like adequate drainage and leaching According U.S. salinity laboratory staff classification depend on (EC, TDS and SAR). Where 87% Excellent water for irrigation sensitive all crops and low likelihood of soil problems According Boron content. Consequently, it is recommended to prevent the sewage and domestic waste water, and the industrial waste water from direct disposal without treatment to the irrigation canals and River Nile; controlling the use of fertilizers and pesticides in the agriculture purposes; selected the suitable crops for every sector (area) according to the chemical characters of the available irrigation water and soil properties.

New isolation process for bioactive food fiber from wild strawberry leaf

Much attention has been paid recently to developing greener and sustainable technologies in the herbal medicine industry, which produces large amounts of waste. This work proposes a clean approach to isolating bioactive food fiber as polyphenolic-polysaccharide conjugates (PPCs) by combining ultrafiltration (UF) with shortening the process time, lowering the energy input, improving the water management, and reducing the organic solvent consumption while maintaining an acceptable yield and biological activity with higher selectivity for PPCs. A simple procedure using UF has high potential for industrial approaches. Leaves of wild strawberry (Fragaria vesca L.), which are waste from plant cultivation, were used. The study schedule was planned using modern experimental design with response surface methodology. The chemical character of the optimal product, its bioactivity, and its mechanisms of action were found to be similar to those of the isolate obtained conventionally. The product was highly branched arabinogalacturonan complexed with a lignin-type polyphenolic matrix containing three fractions with molar masses (Mp) of approximately 180 × 103, 12 × 103, and 6 × 103 g × mol−1. The optimal product and its fractions had anticoagulant activity on human blood plasma by serving as a Factor Xa inhibitor when mediated by antithrombin or as a Factor IIa inhibitor through the creation of complex with heparin cofactor II. The optimal product was more selective in its action than the conventionally obtained product.

Selective Cation Transport through Graphene in Nafion | Graphene | Nafion Membranes

Graphene and related two-dimensional (2D) materials are being intensively studied for use in membrane separators. The ultrathin nature of 2D materials combined with the opportunities they afford for intentional creation of nanometer-sized pores having controllable size and chemical character could allow for membrane separations with high flux and also high selectivity. Proton transport through graphene is especially interesting because it may occur through the intact pristine graphene rather than through defects / pores. Other cations, for example lithium or sodium, may pass through graphene but that transport is through to occur through defects / pores. This presentation will focus on selective cation transport through graphene layers that are embedded between Nafion membranes. Ion transmission through graphene is measured using a four-electrode cell in which two Luggin capillaries sense the potential difference that develops across the membrane in response to an ion current that is driven by a pair of platinum wire drive electrodes. Proton transmission in this cell configuration occurs more than 100 times faster than transport of any other ion. This difference is thought to reflect the different mechanisms by which protons and other cations pass though graphene. The lecture will discuss defect characterization in CVD graphene films, and will consider the role of defects, which are in fact nanopores, in allowing for selective transport of ions through graphene.

Preparation and properties study of graphene-enhanced acid-resistant anticorrosion coating for subsea oil and gas

In order to solve the corrosion problem of the existence of acidic material such as H2S, CO2 in the subsea pipelines, this article studied the coating film forming matter, which is combined with phenolic epoxy resin and phenolic aldehyde amine, acid-resistant filler system, etc. With the addition of the graphene dispersion, it significantly improves the abrasive resistance, salt fog resistance, adhesion and chemical character. This article took out the coating with good acid resistance. The results showed that the acid-resistant anticorrosion coating enhanced by graphene has excellent comprehensive physical and chemical properties, such as salt fog resistance, chemical resistance, hydrogen sulfide corrosion resistance, and alkali resistance, which meet the corrosion protection requirements of H2S and CO2 in acidic oil and gas fields subsea pipelines.

Environmental risk analysis of The Bedadung Watershed By Using DPSIR

Bedadung River is one of the most strategicrivers located in the Bedadung Watershed in Jember. This river crosses Jember with a length of 46,875 meters and it is used as a source of raw water and irrigation as well as a source for PDAM in Jember. Along with many activities of the community, the water pollution load increases significantly. In general, the source of pollution comes from anthropogenic activities in the form of exposure to domestic waste, industrialization, population growth, pesticides and fertilizers, organic and inorganic waste, urban development and weak management systems. This study aims to analyze the environmental risks in the bedadung watershed based on water quality data using DPSIR method. The DPSIR (Driver-Pressure-State-Impact-Response) framework has been used as one of the tools in environmental risk analysis that shows the existence of linear interactions between human activities-pressure and impact. In general, human activities are part of the drivers and human needs that can cause pressure on the environment. This pressure has the potential to cause certain negative impacts that need handling to reduce it. The DPSIR framework which being used is Driver (industry, garbage); Pressure (changes in the chemical composition of water); State (physical and chemical characters); Impact (changes in water quality); and Response (limiting waste disposal to rivers).

Systematic Model Development for Impedance Response of LiCoO2|C Batteries

The objective of this presentation is to describe a systematic approach to model development that includes use of graphical methods to guide model development, use of electrical circuits to account for the geometry of a given system, and use of a phasor notation to facilitate calculation of a faradaic impedance based on proposed reaction mechanisms and mass transfer. The approach is represented for a set of data collected by Erol et al.1 from a commercial LiCoO2|C coin cell battery.The normal operating potential range of the cells reported by the suppliers is between 3.0 V (0% state-of-charge) and 4.2 V (100% state-of-charge). In one experiment, a coin cell was initially discharged under constant 2 mA current to 3.00 V. The battery was then subjected to sequential 80 mV steps in cell voltage down to 2.20 V. After reaching a steady state, the battery was allowed to relax for two days at the open-circuit condition. When held at open circuit, the over-discharged battery slowly reached a cell potential within the normal operating range. Three impedance spectra, taken during the self-charge process, are used to demonstrate a systematic model development. 1. The three spectra were treated as pseudo-replicates, and the measurement model analysis was applied to identify the stochastic error structure. 2-4 2. The measurement model was used to evaluate consistency with the Kramers-Kronig relations to determine the frequency range suitable for analysis.2-4 3. An interpretation model was developed based on the treatment presented by Erol and Orazem5 for the coin cells within the usual operating potential range. An anomalous diffusion model was used to account for the diffusion impedance within the cathode.6 4. The process model was regressed to the Kramers-Kronig-consistent portion of the spectrum using a Levenberq-Marquardt regression algorithm.Impedance spectroscopy is not a stand-alone technique, and models for impedance are not unique. The model identified by the procedure described in this presentation represents a process model intended to account for the hypothesized physical and chemical character of the system under study. The objective of the model is not to provide a good fit with the smallest number of parameters. The objective is rather to use the model to gain a physical understanding of the system. The model should be able to account for, or at least be consistent with, all experimental observations. The proposed model can suggest experiments needed to validate model hypotheses.

How accurate are TD-DFT excited-state geometries compared to DFT ground-state geometries?

In this work, we take a different angle to the benchmarking of time-dependent density functional theory (TD-DFT) for the calculation of excited-state geometries by extensively assessing how accurate such geometries are compared to ground-state geometries calculated with ordinary DFT. To this end, we consider 20 medium-sized aromatic organic compounds whose lowest singlet excited states are ideally suited for TD-DFT modeling and are very well described by the approximate coupled-cluster singles and doubles (CC2) method, and then use this method and six different density functionals (BP86, B3LYP, PBE0, M06-2X, CAM-B3LYP, and ωB97XD) to optimize the corresponding ground- and excited-state geometries. The results show that although each hybrid functional reproduces the CC2 excited-state bond lengths very satisfactorily, achieving an overall root mean square error of 0.011 Å for all 336 bonds in the 20 molecules, these errors are distinctly larger than those of only 0.004-0.006 Å with which the hybrid functionals reproduce the CC2 ground-state bond lengths. Furthermore, for each functional employed, the variation in the error relative to CC2 between different molecules is found to be much larger (by at least a factor of 3) for the excited-state geometries than for the ground-state geometries, despite the fact that the molecules/states under investigation have rather uniform chemical and spectroscopic character. Overall, the study finds that even in favorable circumstances, TD-DFT excited-state geometries appear intrinsically and comparatively less accurate than DFT ground-state ones.

Характеристика почвенного покрова Апшерона и состояние использования земельного фонда

The morphogenetic analysis of the soils in Absheron administrative region was analyzed, the peculiarity of the ecological factors affecting the formation of physical, physico–chemical characters was given. The composition of soil fund is analyzed. An area of clayey, heavy, average, light clayey, sandy soils was calculated. Land grouping was performed for soil profile density. The analysis was performed on administrative–zone units of the areas in the agricultural places (tillage, perennial planting, pastures and hay field), the distribution legislation of the land property forms was studied.

Aplikasi Kotoran Sapi untuk Perbaikan Sifat Kimia Tanah dan Pertumbuhan Vegetatif Bibit Kelapa Sawit (Elaeis guineensis Jacq.) pada Media Sub Soil

Standar media tanam untuk bibit kelapa sawit adalah top soil dengan kan-dungan bahan organik yang cukup. Meskipun demikian, pada kondisi tertentu seperti di lahan mineral marjinal dimana top soil sudah tererosi berat, sehingga top soil sulit didapat. Pada kondisi demikian maka sub soil digunakan sebagai media tanam. Sifat fisik, kimia, dan biologi sub soil umumnya kurang memenuhi syarat untuk digunakan sebagai media tanam, namun sifat tersebut masih mungkin diperbaiki dengan me-nambahkan bahan pembenah tanah. Penelitian ini bertujuan untuk mengetahui pengaruh kombinasi bahan pem-benah tanah dalam bentuk kotoran sapi (notasi O, taraf 0 dan 5%) dan pemupukan anorganik standar (notasi S, taraf 0; 25; 50; 75; dan 100%) terhadap perubahan sifat kimia media sub soil dan pertumbuhan bibit kelapa sawit. Penelitian disusun meng-gunakan rancangan acak kelompok dengan 7 perlakuan yaitu kontrol (O0S0), standar pupuk anorganik (O0S100), dan 5 perlakuan lainnya yang merupakan kombinasi antara 5% kotoran sapi dengan berbagai taraf standar pupuk anorganik (O5S0, O5S25, O5S50, O5S75, dan O5S100). Hasil penelitian menunjukkan bahwa aplikasi 5% kotoran sapi meningkatkan ketersediaan bahan organik, kapasitas tukar kation, dan hara tersedia di media sub soil. Meskipun O5S50 (kombinasi aplikasi 5% kotoran sapi dan 50% pupuk anorganik standar telah menghasilkan nilai Efektivitas Agronomi Nisbi (EAN) di atas 100%, pertumbuhan vegetatif bibit kelapa sawit terbaik diperoleh pada per-lakuan O5S100 (kombinasi aplikasi 5% kotoran sapi dan 100% dosis pupuk anorganik standar).