Method For Synthesis Research Articles

A new method for synthesis and designing transmissive linear-to-circular polarization converters based on branch line circuit model

ABSTRACT This paper proposes a new design method of a linear-to-circular polarization converter based on the branch line circuit model. The series branches are implemented by dielectric spacers and the shunt branches are implemented by anisotropic admittance sheets. The admittance matrix of the anisotropic admittance sheets is derived by even and odd mode analysis. A unit cell consisting of two metal layers and a dielectric spacer is then designed using an iterative algorithm for operation from 15.5 to 23 GHz. Results indicate that the axial ratio and insertion loss of the designed polarizer are better than 3 and 1.5 dB respectively, for incident angles between ±45°. To validate the simulation results, a waveguide-based test setup is designed and fabricated, with measurement results indicating good agreement with simulations. The proposed method can be potentially applied to design other anisotropic structures such as half-plate polarizers and polarization rotators.

The Influence of Shakarim Kudaiberdiev’s Work on the Economic, Cultural, and Spiritual Development of Kazakhstan in the Late 19th Century and Early 20th Century

The significance and relevance of the issues are predetermined by the fact, that, by the time of Shakarim Kudaiberdiev’s activity, the political and social situation of Kazakhstan in the early 20th century was on the verge of collapse. The main factor that influenced this situation was the policy of spreading illiteracy, people alienated from religion language, and writing. From the late 19th and early 20th centuries, Kazakhstan suffered from the colonial policies of the Russian Empire. Currently Kudaiberdiev writes a work “Catechism of Muslims”. The main purpose of the study is to analyze the consequences of the creative work on the economic and spiritual and cultural development of Kazakhstan. During the analysis, several scientific sources and materials were analyzed, and the following scientific methods were used: structural-functional and dialectical methods, the method of synthesis, logical and comparative analysis, and the method of generalization. During the research, it was proved that in the works of Shakarim Kudaiberdiev the calls to fight against the policy of tsarist Russia and to revive their language, customs, religion, and history were present. The main result of this research is proof that the works of Shakarim Kudaiberdiev had a tremendous impact on the social status, culture, religion, and language of the Kazakh people. His works acted in opposition to Russian policy and encouraged people who were tired of colonial oppression. The research on this issue is actively developed, therefore this work is of practical value for the definition of the role of Shakarim’s creativity during the economic, cultural, social, and political development of Kazakhstan at the end of 19 – the beginning of 20 century.

Continuous synthesis of drug particles via spray drying of emulsions obtained by mechanical emulsification and ouzo effect

In the pharmaceutical field, nanoparticle formulation is an effective approach to improve the solubility of poorly water-soluble drugs. Spray drying is used for the synthesis of fine drug particles. The particle size obtained by spray drying generally depends on the size of the sprayed droplet. In this study, an emulsion spray drying method is proposed as a novel method for nanoparticle synthesis. Oil-in-water (O/W) nanoemulsions containing oil-soluble drugs were prepared. Spraying O/W emulsions could produce fine particles with the size of 122 nm. The particles obtained by emulsion spray drying were smaller than those obtained by spray drying without an emulsion. Furthermore, an Ouzo emulsion, which is a self-emulsification method, was investigated to improve the particle yield. The particles obtained by spray drying of the Ouzo emulsion had the size of 0.50 μm, which was smaller than those obtained without the Ouzo emulsion. Moreover, in-vitro dissolution tests were performed to evaluate the solubility of the obtained particles as well as the unprocessed drug powder. The particles obtained via spray drying of the Ouzo emulsions showed the highest dissolution rate. In summary, spray drying of O/W and Ouzo emulsions resulted in the production of fine drug particles.

Interaction of politics and religion as a factor in shaping the religious culture of Kyrgyzstan’s youth

Democracy and frequent changes of government in Kyrgyzstan contribute to the spread of various religious movements in the country. Social processes, political shifts and the spread of radical religious ideas among young people emphasize the relevance of this study. The purpose of this article is to assess the impact of Kyrgyzstan's religious policy on the religious consciousness of contemporary youth. The study used general scientific methods of analysis and synthesis, generalization, historical and critical, comparative, dialectical, as well as empirical methods of surveys and questionnaires. The study showed that the religious policy of Kyrgyzstan is characterized by democracy and liberalism, based on the secular nature of the state. Kyrgyzstan is a multi-confessional country, with more than 30 religions. The vast majority of Kyrgyzstan's population are Sunni Muslims, and the second most common religious denomination is Orthodox Christianity. Since 1991, Kyrgyzstan has witnessed a process of Islamization, and non-traditional religious movements, both Islamic and other religious doctrines, have also penetrated and gained popularity in the country. The state's liberal policy in the field of religion facilitates the penetration of non-traditional religious organizations from abroad into Kyrgyzstan. Young people are particularly susceptible to new religious movements. This phenomenon can lead to the spread of radical religious ideas among the youth of Kyrgyzstan. In this regard, the state should pay closer attention to the policy in the field of religion. The practical value of the work is determined by the fact that its results can be useful in further research on this issue.

Surface state modulation of carbon dots for efficient generation of hydrogen peroxide

Electrocatalytic dual electron oxygen reduction to hydrogen peroxide (2e ORR) is considered a special and sustainable method for on-site continuous production of hydrogen peroxide. Oxygen doped carbon based materials have demonstrated their superiority in the generation of H2O2. However, there is still a lack of direct experimental evidence to determine the true active site on complex carbon surfaces. In this work, we introduce only carboxyl functional groups on the surface of carbon dots by a mild and simple synthesis method to study the specific COOH functional groups on the generation of H2O2. The H2O2 selectivity was correlated with the contents of COOH functional groups. In alkaline environments, the citric acid modified CDs (CA-OCDs) own excellent catalytic ability for 2e ORR, showing a maximum starting potential of 0.829 V (vs. RHE) and a high selectivity of 89.7% over a wide potential range of 0.2-0.7 V (vs. RHE). In actual H2O2 production, the Faraday efficiency (FE) of CA-OCDs can be up to 97%, and the yield achieves 838 mmol gcatalyst-1 h-1. This work provides an effective and simple strategy for designing efficient carbon-based catalysts for sustainable H2O2 electrosynthesis.

Environmental risk mitigation of lambda-cyhalothrin using tryptophan-modified magnetic nanoparticles: A sustainable emergency response strategy

Lambda-cyhalothrin, a synthetic pyrethroid pesticide extensively used in agriculture, poses significant environmental challenges due to its extensive and long-term application. To remediate pollution caused by such organic contaminants, our study introduces a rapid and convenient one-pot synthesis method for creating amino acid-modified magnetic nano-adsorbents (AA-MNPs). Research found that after modification with tryptophan (Trp), the adsorption effectiveness of MNPs on Lambda-cyhalothrin significantly increases. This modification enhances the carbon content of the magnetic nanoparticles, while minimally affecting the magnetic saturation of the MNPs. Trp-MNP exhibited an approximate particle size of 450 nm and a specific surface area of 52.36 m2/g. The isotherm and kinetic experiments were well-fitted to the Liu isotherm model and the pseudo-second-order model, respectively. Thermodynamic assessments suggested that the adsorption process is spontaneous and exothermic. Results indicated that the maximum adsorption capacity 144.34 mg g−1 for Trp-MNPs at 298 K, outperforming adsorbents reported in the literature. The half-adsorption time was reduced to 8 min at 298 K with an initial concentration of 60 mg/L. This enhancement was likely influenced by the aromatic ring modification and hydrophobicity of Trp-MNPs. The study explored potential removal mechanisms from a tri-phase perspective, investigating the interactions between the adsorbent, adsorbate, and solvent.

Effects of Cr doping and size reduction on the structural and magnetic properties of α–CoV2O6

We report the effect of Cr-doping on the structural and magnetic properties of powder α–CoV2O6 samples. Samples were synthesized using a wet chemical synthesis method and calcined at temperatures between 350 ℃ and 500 ℃ to promote phase formation. For α–CoV2O6 and Cr-doped α–CoV2O6 samples, a single phase only occurs when the samples are calcined at 450 ℃ and 500 ℃, respectively, as confirmed using powder x-ray diffraction (XRD). Cr-doping results in a compression distortion of the lattice along the c-axis. Transmission electron microscopy (TEM) measurements indicate that Cr-doping causes a reduction in particle size and particle agglomeration. Metamagnetism was observed in field dependence of magnetization, M(μ0H) for α–Co(V1−xCrx)2O6 samples with 0 ≤ x ≤ 0.05. The hysteresis in M(μ0H) curves for μ0H < 5T at 2K indicate that the magnetization is metastable and suggests magnetic irreversibility. Zero-field-cooled (ZFC) and field-cooled (FC) temperature dependence of magnetization, M(T), show antiferromagnetic (AFM) ordering of the α–Co(V1−xCrx)2O6 samples at fields, μ0H ≤ 1T. Increasing field strength to 2.5T causes a transition from the AFM state to a ferrimagnetic (FI) state, and an introduction of spin-glass (SG)-like behavior. At 5T, a transition from the FI state to a ferromagnetic (FM) state and a suppression of SG-like behavior is observed.

Microstructures and properties of Al2O3 dispersion-strengthened Cu10Sn oil bearings prepared by solid-liquid doping and reactive synthesis method

To modify the shortcomings of Cu10Sn oil bearing in mechanical performance, this work proposes to prepare the Al2O3 oxide dispersion strengthened (ODS) Cu10Sn oil bearings by reactive synthesis using elemental Sn and Al2O3 ODS-Cu powder, among which the uniformly doped Al2O3 ODS-Cu powder was synthesized through a solid-liquid doping of Al(NO3)3 in CuO powders followed with hydrogen reduction. The effects of Al2O3 content on the microstructure and properties of ODS-Cu powder and ODS-Cu10Sn oil bearings were investigated in details. The results showed that an increase in Al2O3 amount from 0 to 1.5wt.% leads to a decrease in the average particle size of the reduced ODS-Cu powders, and contributes to the significant improvement of radial compressive strength, and Vickers microhardness. The appropriate sintering temperature is approximately 800 °C, which can result in the evenly distributed Al2O3 and well-developed porosity in oil bearing sample after sintering. The corresponding compressive strength and microhardness of ODS1.5-Cu10Sn oil bearing can reach 305MPa and 208 HV respectively.

Synthesis, Characterization, and Optimization of Novel Furan-ring Fused Chalcones via Radical Cyclization of α,β-Unsaturated Ketones and Cyclic Ketone

Abstract: Novel Furan-ring Fused Chalcones (FFC) were synthesized using a radical cyclization reaction of α,β-unsaturated ketones with cyclic ketone as the model reaction to attain this goal. In this study, traditional and microwave-assisted methods for the efficient and cost-effective synthesis of furan-ring fused chalcones in mild reaction conditions are compared and optimized. The goal is to develop a reliable and adaptable synthetic technique that may be used to produce these useful chalcone derivatives quickly and effectively. The optimal experimental conditions for these reactions were carefully determined using two independent methodologies: conventional (Method A) and microwave (Method B). The results indicated that the proposed method B could be used effectively in the future to synthesize novel furans with short reaction times and acceptable yields (87-94 %), and products were purified by column chromatography and preparative thin layer chromatography (PTLC). All new compounds were characterized by 1H-NMR, 13C-NMR, LC-MS, and elemental analyses.

Immobilization of Xylanase on ZnO nanoparticles obtained by green synthesis from Eupatorium cannabinum L. and its application in enrichment of fruit juices

Juice production is one of the main components of the nutritional food industry. Therefore, improving fruit juice quality and preventing the formation of negative by-products is important for human health. The role of environmentally friendly, safe and economically more affordable green nanocarriers in improving the quality of fruit juice is increasing day by day. For this purpose, zinc oxide nanoparticles (ZnONPs) were prepared from the aqueous extract of the Eupatorium cannabinum L. using the green synthesis method. After immobilization, structural and morphological characterizations of the prepared ZnONPs and xylanase (Xyl)@ZnONPs were carried out, which confirmed that both the synthesis of ZnONPs and the immobilization of Xyl enzyme on ZnONPs were successfully carried out. The biochemical parameters of Xyl@ZnONPs such as optimum pH and temperature, kinetic parameters, thermal stability, reusability, and storage stability were investigated and compared with free Xyl. After immobilization, the optimum pH of free Xyl shifted from 5.0 to an alkaline pH of 8.0, while no change in the optimum temperature (70 °C) was observed for both enzymes. While the activation energy of free Xyl was 5.56 kJ/mol, it was found to be 7.27 kJ/mol for Xyl@ZnONPs. Xyl@ZnONPs outperformed free Xyl due to its long-term storage stability and reusability. Moreover, Xyl@ZnONPs retained 50 % of its activity after 5 reuses and 87 % of its activity after 4 weeks of storage at room temperature. In addition, a decrease in Km value and an increase in Vmax value were observed after immobilization, which means the increased catalytic activity of the Xyl@ZnONPs. As a result of re-using Xyl@ZnONPs in orange juice for 6 cycles, clarification yield of 66.43 % was obtained under optimized conditions. Overall, this study prepared a suitable, environmentally friendly, and robust carrier support for Xyl immobilization and developed a biocatalyst that will provide high performance in the industrial field.

One-pot synthesis of benzothiazole derivatives using Bovine serum albumin and Novozym435

This study presents a one-pot synthesis method involving a Michael acceptor formation via condensation reaction between aldehyde and benzothiazole-2-acetonitrile catalyzed by bovine serum albumin (BSA), followed by a decarboxylative Michael addition reaction using keto esters as nucleophiles and immobilized lipase (Novozym435) as a catalyst. This approach enabled the synthesis of 11 derivatives of 2-(benzo[d]thiazol-2-yl)-5-oxo-3-arylhexanenitrile with yields ranging from 54% to 91%.

Green Synthesis of Silver Nanoparticles Using Aqueous Fruit Peel Extract of Citrus aurantifolia: Optimization, Its Characterization and Stability Test

In this present study, silver nanoparticles were synthesized by green biological synthesis method using plant extract from fruit peel of Citrus aurantifolia as reducing agents. All the parameters in the synthesis of silver nanoparticles (AgNPs) were optimized to achieve a better yield, controlled size and stability of the particles. The biosynthesis of silver nanoparticles was monitored via UV-vis spectrophotometer and stability test was done. The resulting UV-Vis spectra of synthesized AgNPs from C. aurantifoliafruit peel extract (CAFPE) showed standard surface plasmon resonance band at 420 nm which indicated the presence of AgNPs. The optimum result was obtained with an optimum concentration at 4 mM AgNO3, leaving in a dark room temperature for 24 h and using a concentration 1:3 ratio (extract: silver nitrate). Moreover, the stability of the CAFPE-AgNPs was also observed after 30 days of synthesis and even up to 10 months, indicating optimization plays major role towards the stability fate of nanoparticles. The FTIR analysis showed possible functional groups of biomolecules that play roles in the bioreduction and capping of silver nanoparticles. In addition, it is believed that these parameters are highly suitable for bulk production of single spherical AgNPs with diameter 29.6- 45.2 nm confirmed via FESEM. Thus, the obtained results clearly suggest that optimization of silver nanoparticles may have important role in attaining a better yield and stability of metal nanoparticles, refraining back to its original structure or particles.

Synthesis of All-Peptide-Based Rotaxane from a Proline-Containing Cyclic Peptide.

Rotaxane cross-linkers enhance the toughness of the resulting rotaxane cross-linked polymers through a stress dispersion effect, which is attributed to the mobility of the interlocked structure. To date, the compositional diversity of rotaxane cross-linkers has been limited, and the poor compatibility of these cross-linkers with peptides and proteins has made their use in such materials challenging. The synthesis of a rotaxane composed of peptides may result in a biodegradable cross-linker that is compatible with peptides and proteins, allowing the fortification of polypeptides and proteins and ultimately leading to the development of innovative materials that possess excellent mechanical properties and biodegradability. However, the chemical synthesis of all-peptide-based rotaxanes has remained elusive because of the absence of strong binding motifs in peptides, which prevents an axial peptide from penetrating a cyclic peptide. Here, we synthesized all-peptide-based rotaxanes using an active template method for proline-containing cyclic peptides. The results of molecular dynamics simulations suggested that cyclic peptides with an expansive inner cavity and carbonyl oxygens oriented toward the center are favorable for rotaxane synthesis. This rotaxane synthesis method is expected to accelerate the synthesis of peptides and proteins with mechanically interlocked structures, potentially leading to the development of peptide- and protein-based materials with unprecedented functionalities.

Multifunctional Nanocomposites in B4C-Tic-Tib2-Sic-BN-Al2O3-Sialon-C Carbon Fiber System for Armor Fillets, Turbine Discs and Wings, High-Temperature Wear Resistant Nodes

Goal - to receive on first stage β - SIALON containing nanocomposites by reactive sintering method at 14000C, with nitrogen pro-cess from origin composition in TiC-BN-SiC-B4C-Si-Al-Al2O3 (nanopowder) system. By using this method of synthesis, it became possible to receive nanocomposites with different percentages of β - SIALON. Our task was to study the phase composition of re-ceived consolidated materials in the TiC-TiB2-BN-SiC-B4C-β-SiAlON-Al2O3 (nanopowder-400nm.) system. Method. The obtained mass was grounded in an attritor and the consolidated composite was obtained by hot pressing at 16200C during 40 minutes, with glass perlite (Armenia) dope 2 mass%, delaying at final temperature for 8 min, under 30 MPa pressure and vacuum – 10-3 Pa. Perlite from Aragatc contained 96 mas. % glass. To study the phase composition of the composites, we conducted an X-ray structural analysis on the DRON-3 device. And to study the microstructure, we conducted research on an optical microscope -AC100 and a raster electron microscope “Nanolab 7” of the company "OPTON”. The values of the electrical parameters of the studied composites were calculated on the basis of the ob-tained "lgp- t" dependence. We have studied mechanical properties. Result. In TiC-TiB2-BN-SiC-B4C- β-SiAlON-Al2O3 – C Carbon Fiber system we obtained nanocomposites with high mechanical proper-ties. The advantage of this method is that compounds, which are newly formed thanks to interaction going on at thermal treat-ment: Si3N4, Si, AlN are active, which contributes to β-SiALON formation at relatively low temperature, at 1300-13500C. It is evi-dent that inculcation of ALN in crystal skeleton of ß-Si3N4 is easier since at this temperature interval crystal skeleton of Si3N4 is still in the process of formation. ß-SiAlON was formed at 14500C. Part of boron carbide was transformed into boron nitride in ni-trogen environment and in titanium diboride, which in the case of both composites is in small quantities. Conclusion. The phase composition of the obtained composite provides high physical-technical and performance properties of these nanocomposites. Compression strength-2198 MPa, Bending strength-271 MPa, Thermal expansion coefficient a20-700-3.8 10-6 0C.

Electric Field Effects in Flash Joule Heating Synthesis.

Flash Joule heating has emerged as an ultrafast, scalable, and versatile synthesis method for nanomaterials, such as graphene. Here, we experimentally and theoretically deconvolute the contributions of thermal and electrical processes to the synthesis of graphene by flash Joule heating. While traditional methods of graphene synthesis involve purely chemical or thermal driving forces, our results show that the presence of charge and the resulting electric field in a graphene precursor catalyze the formation of graphene. Furthermore, modulation of the current or the pulse width affords the ability to control the three-step phase transition of the material from amorphous carbon to turbostratic graphene and finally to ordered (AB and ABC-stacked) graphene and graphite. Finally, density functional theory simulations reveal that the presence of a charge- and current-induced electric field inside the graphene precursor facilitates phase transition by lowering the activation energy of the reaction. These results demonstrate that the passage of electrical current through a solid sample can directly drive nanocrystal nucleation in flash Joule heating, an insight that may inform future Joule heating or other electrical synthesis strategies.

MXenes-polymer nanocomposites for biomedical applications: fundamentals and future perspectives

The article discusses the promising synergy between MXenes and polymers in developing advanced nanocomposites with diverse applications in biomedicine domains. MXenes, possessing exceptional properties, are integrated into polymer matrices through various synthesis and fabrication methods. These nanocomposites find applications in drug delivery, imaging, diagnostics, and environmental remediation. They offer improved therapeutic efficacy and reduced side effects in drug delivery, enhanced sensitivity and specificity in imaging and diagnostics, and effectiveness in water purification and pollutant removal. The perspective also addresses challenges like biocompatibility and toxicity, while suggesting future research directions. In totality, it highlights the transformative potential of MXenes-polymer nanocomposites in addressing critical issues across various fields.

Green synthesis of silver nanoparticles using Hebeloma excedens mushroom extract as a new source: Anti-lipid peroxidation, bioaccessibility and antidiabetic properties

AbstractA traditional source of natural bioactive compounds, mushrooms are used to synthesize biomaterials, thanks to their potential applications in the medicine, pharmacology and cosmetics industries. In this study, the vitamin C and E contents of the Hebeloma excedens mushroom species were determined as 64.2 mg/g and 38.6 mg/g, respectively. In the mineral substance analysis, the highest amount of magnesium (32.16 mg/g) and trace amounts of iron (0.22 mg/g) were detected. In the nanoparticles (AgNPs/He) synthesized using this mushroom species, the colour of the mixture first changed to dark brown and exhibited maximum absorption at 428 nm, corresponding to the surface plasmon resonance. Fourier transform infrared spectroscopy (FTIR) results revealed the binding properties of the biocomponents responsible for coating and stabilizing the nanoparticles. The resulting nanostructures were much more stable than the mushroom extract and showed strong antioxidant activity (22.93 mg/ml). A significant decrease in phenolic compounds was observed after the gastrointestinal digestion process applied to the mushroom extract and AgNPs/He samples (p &lt; 0.05). However, a significant increase in the bioaccessibility of phenolic compounds was detected in AgNPs/He particles (p &lt; 0.05). It was determined that there was a significant increase in the thermal stability, inhibition against lipid peroxidation (6.64 mg/ml) and antidiabetic activities (29.20 mg/ml) of silver structures synthesized using the green synthesis method. As a result, the existence and current potential of a new biomaterial suitable for cost-effective and large-scale production in the synthesis of AgNPs/He has been demonstrated for the first time.

Calcium Zirconate: Methods of Synthesis and Applications of Ceramic and Refractory Materials Based Thereon — A Review. Part 2. Applications of Ceramic and Refractory Materials Based on Calcium Zirconate

Calcium Zirconate: Methods of Synthesis and Applications of Ceramic and Refractory Materials Based Thereon — A Review. Part 2. Applications of Ceramic and Refractory Materials Based on Calcium Zirconate

Effect of the Composition and Synthesis Method on the Sorption Properties of NaNO3/MgO Sorbents with Respect to Carbon Dioxide

Effect of the Composition and Synthesis Method on the Sorption Properties of NaNO3/MgO Sorbents with Respect to Carbon Dioxide

Photoelectrocatalytic Synthesis of Urea from Carbon Dioxide and Nitrate over a Cu2O Photocathode

Transformation of carbon dioxide and nitrate ions into urea offers an attractive route for both nitrogen fertilizer production and environmental remediation. However, achieving this transformation under mild conditions remains challenging. Herein, we report an efficient photoelectrochemical method for urea synthesis by co‐reduction of carbon dioxide and nitrate ion over a Cu2O photocathode, delivering urea formation rate of 29.71±2.20 μmol g−1 h−1 and Faradaic efficiency (FE) of 12.90±1.15 % at low external potential (−0.017 V vs. reversible hydrogen electrode). Experimental data combined with theoretical calculations suggest that the adsorbed CO* and NO2* species are the key intermediates, and associated C−N coupling is the rate‐determining step. This work demonstrates that Cu2O is an efficient catalyst to drive co‐reduction of CO2 and NO3− to urea under light irradiation with low external potential, showing great opportunity of photoelectrocatalysis as a sustainable tool for value‐added chemical synthesis.