Nano Studies

Produce archwires and braces in orthodontics by 3D printing methods: Review

Sahand Rajabkheir, Parisa Ganjinia — Sun, 25 Aug 2024 00:00:00 +0400

Produce archwires and braces in orthodontics by 3D printing methods: Review. / S. Rajabkheir, P. Ganjinia. Nano Studies. – 2023–2024. – # 23/24. – pp. 7-26. – eng.

3D and 4D printing are cutting-edge technologies for exact and expedited manufacturing of objects ranging from plastic to metal. Recent advances in 3D and 4D printing technologies in dentistry and orthodontic appliances and orthotics, implants, etc., 3D printing techniques that are increasing their antimicrobial and relevant mechanical properties, such as surface topography, friction or corrosion resistance, hydrophobic properties and features, has been presented. In this review, different 3D printing technologies available for use in dentistry are highlighted together with a judgment on the materials available for printing. Tab. 1, Fig. 8, Ref. 61.

Scrutinize progressive approach in construction of micro/nano 3D networks

Parisa Ganjinia, Mohammad Dehghanpour — Sun, 25 Aug 2024 00:00:00 +0400

Scrutinize progressive approach in construction of micro/nano 3D networks. / P. Ganjinia, M. Dehghanpour. Nano Studies. – 2023–2024. – # 23/24. – pp. 27-38. – eng.

Mesh structures are used as engineering materials for industrial and resistant light structures. The emergence of nanotechnology and the ability to manufacture and control the size of structures in micro/nano-dimensions has led to the manufacture and design of engineering materials in tiny dimensions. Reticulated and engineered 3D structures in nano dimensions have been widely researched nowadays. By using different manufacturing and design tools such as geometric design, structural optimization, and material size effects in small dimensions, various types of 3D micro-nano-materials have been made so far. This article describes recent advances in the design and fabrication of micro/nano networks as a 3D arrangement. Fig. 8, Ref. 40.

Nanoparticle synthesis and characterization of Li–Mg–Al ferrites: Potential applications in capacitor and magnetic storage media

Sun, 25 Aug 2024 00:00:00 +0400

Nanoparticle synthesis and characterization of Li–Mg–Al ferrites: Potential applications in capacitor and magnetic storage media. / S. S. Tirlapur, V. V. Tambe, S. S. Kakati, Sh. N. Mathad, S. V. Angadi, D. B. Shirgaonkar, A. S. Pujar, S. L. Galagali, P. R. Jeergal, C. S. Hiremath, R. B. Pujar. Nano Studies. – 2023–2024. – # 23/24. – pp. 39-50. – eng.

This study presents the synthesis and characterization of Li_0.50Mg_0.75AlxFe_2–xO₄ ferrite nanoparticles, where x varies from 0.15 to 0.60. The synthesized nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), Fourier-transform infrared (FTIR) spectroscopy, dielectric properties and vibrating sample magnetometry (VSM). The XRD analysis showed that all the samples have a single-phase fcc spinel structure. The SEM images revealed the formation of spherical nanoparticles with a size range of 11–39 nm. EDX analysis confirmed the presence of constituent elements and Al substitution. FTIR spectra indicated the characteristic vibrational frequencies corresponding to metal–oxygen bonds in the spinel structure. The dielectric properties of the samples were studied as a function of frequency and temperature. The dielectric constant and dielectric loss showed a decrease with an increase in frequency. The VSM measurements showed that all the samples exhibit ferrimagnetic behavior. The magnetic properties were observed to be dependent on Al substitution with a decrease in saturation magnetization. The results indicate that Li_0.50Mg_0.75Al_xFe_2–xO₄ nanoparticles have potential applications in various fields such as capacitors, and magnetic storage media. Fig. 4, Tab. 5, Ref. 28.

Direct and indirect restoration: Review

Parisa Ganjinia, Sahand Rajabkheir, Fatemeh Azim — Sun, 25 Aug 2024 00:00:00 +0400

Direct and indirect restoration: Review. / P. Ganjinia, S. Rajabkheir, F. Azim. Nano Studies. – 2023–2024. – # 23/24. – pp. 51-76. – eng.

Restorative dentistry has ripened from the need to treat dental diseases, particularly caries. This demand often is escorted by the conditional necessity of maintaining the vital strength of the teeth during function and launching a healthy interface between the restoration and the rigid/supporting soft tissue to prevent further breakdown and allow regular maintenance, all within a growing patient-driven request for pain-free and cosmetic treatment. Furthermore, professional dental care demands a more accurate diagnosis of illness, earlier interceptive treatment, and healing prevention of dental disease. Restorative dentistry focuses on fixing or replacing damaged or missing teeth. These methods help enhance oral health and procedure. Common dental restorations include crowns, bridges, and implants. Restorative dental materials are among the most crucial medical appliances regarding the number of patients who profit and the technical complexity of the products, including amalgam, composites, zirconia, etc. This study demonstrates processes for producing materials in direct and indirect restoration. Fig. 20, Tab. 2, Ref. 75.

Some aspects of adsorption, catalytic and photocatalytic interactions of organic dyes with TiO2-based binary nanocomposites

Olena Lavrynenko, Maksym Zahornyi, Olesja Pavlenko — Sun, 25 Aug 2024 00:00:00 +0400

Some aspects of adsorption, catalytic and photocatalytic interactions of organic dyes with TiO₂-based binary nanocomposites. / O. Lavrynenko, M. Zahornyi, O. Pavlenko. Nano Studies. – 2023–2024. – # 23/24. – pp. 77-98. – eng.

Nanocomposites based on titanium dioxide with an anatase structure, modified with noble metals (Ag, Pd, Au) and nanocerium were synthesized using the chemical deposition method. It is shown that nanocomposites form loose aggregates with the size of individual particles in the range of 8–16 nm, which are capable of forming colloid-stable dispersions upon contact with dye solutions. The influence of the nature of the doping admixture on the sorption, catalytic, and photocatalytic properties of nanocomposites during their interaction with solutions of cationic and anionic dyes has been determined. We have investigated that the ZPC (Zero Point of Charge) of most composites was close to neutral and ranged from 6.9 to 9.2. In solutions of dyes, the sign of the particle charge changed due to the possible hydrolysis and deviation of pH values. Maximum adsorption capacity of MB (Methylene Blue) dye is found to be 12.96 mg/g. The effect of increasing the color intensity of the solution upon contact with nanocomposites was revealed, which is due to the sensitization of photocatalysts by the dye molecules. It is shown that the photocatalytic destruction of dye molecules is characterized by a gradual decrease in the intensity of all characteristic bands and is accompanied by a hypsochromic shift of the chromophore band in UV–Vis (UltraViolet–Visible) spectra. At the same time, during the catalytic destruction of dye molecules, the destruction of the chromophoric part of the molecules is faster compared to photocatalysis, but the temperature of the system does not affect the aromatic part of the dye. It was stated that for the effective destruction of organic dyes in an aqueous environment, it is advisable to combine the catalytic process at 50–60°С and the UV or visible light irradiation in 60 min. Fig. 9, Tab. 3, Ref. 49.

Demystifying arrow of time

Zura Kakushadze — Sun, 25 Aug 2024 00:00:00 +0400

Demystifying arrow of time. / Z. Kakushadze. Nano Studies. – 2023–2024. – # 23/24. – pp. 99-118. – eng.

Scientific discussions of the arrow of time often get quite confusing due to highly complex systems they deal with. Popular literature then often coveys messages that tend to get lost in translation. The purpose of this note is to demystify the arrow of time by stripping off the unnecessary complexities and thereby simplifying the discussion. We do this by providing examples that are exactly solvable and make it easy to see the root cause of the apparent “time-irreversibility”. We also discuss “time-reversal” solutions, where the initial state evolves such that it reaches the state which is the same as the initial state moving backward in time. These solutions are simple enough to be comprehensible to a highschooler. We discuss the arrow of time both in the classical and quantum settings, including in the cosmological context. Ref. 51.